diff --git a/src/components/MemberOf/MemberOfAddModalNew.tsx b/src/components/MemberOf/MemberOfAddModalNew.tsx
new file mode 100644
index 000000000..322fa5dfd
--- /dev/null
+++ b/src/components/MemberOf/MemberOfAddModalNew.tsx
@@ -0,0 +1,277 @@
+import React, { ReactNode, useEffect, useState } from "react";
+// PatternFly
+import { Button, DualListSelector } from "@patternfly/react-core";
+// Modals
+import ModalWithFormLayout from "src/components/layouts/ModalWithFormLayout";
+// Data types
+import {
+  Netgroup,
+  Roles,
+  HBACRules,
+  SudoRules,
+  HostGroup,
+  UserGroupNew,
+} from "src/utils/datatypes/globalDataTypes";
+// Hooks
+import { AlertObject } from "src/hooks/useAlerts";
+// Utils
+import { getNameValue } from "./MemberOfTableNew";
+import { ErrorResult, useGroupAddMemberMutation } from "src/services/rpc";
+
+interface ModalData {
+  showModal: boolean;
+  handleModalToggle: () => void;
+}
+
+interface TabData {
+  tabName: string;
+  userName: string; // TODO: Change to a more generalistic name
+}
+
+export interface PropsToAdd {
+  modalData: ModalData;
+  availableData:
+    | UserGroupNew[]
+    | Netgroup[]
+    | Roles[]
+    | HBACRules[]
+    | SudoRules[]
+    | HostGroup[];
+  groupRepository: unknown[];
+  updateGroupRepository: (
+    args:
+      | UserGroupNew[]
+      | Netgroup[]
+      | Roles[]
+      | HBACRules[]
+      | SudoRules[]
+      | HostGroup[]
+  ) => void;
+  updateAvOptionsList: (args: unknown[]) => void;
+  tabData: TabData;
+  alerts: AlertObject;
+}
+
+const MemberOfAddModal = (props: PropsToAdd) => {
+  // Dual list data
+  const data = props.availableData.map((d) => getNameValue(d));
+
+  // API call
+  const [addMemberToUserGroup] = useGroupAddMemberMutation();
+
+  // Dual list selector
+  const [availableOptions, setAvailableOptions] = useState<ReactNode[]>(data);
+  const [chosenOptions, setChosenOptions] = useState<ReactNode[]>([]);
+
+  const listChange = (
+    newAvailableOptions: ReactNode[],
+    newChosenOptions: ReactNode[]
+  ) => {
+    setAvailableOptions(newAvailableOptions.sort());
+    setChosenOptions(newChosenOptions.sort());
+  };
+
+  const fields = [
+    {
+      id: "dual-list-selector",
+      pfComponent: (
+        <DualListSelector
+          isSearchable
+          availableOptions={availableOptions}
+          chosenOptions={chosenOptions}
+          onListChange={(
+            _event,
+            newAvailableOptions: ReactNode[],
+            newChosenOptions: ReactNode[]
+          ) => listChange(newAvailableOptions, newChosenOptions)}
+          id="basicSelectorWithSearch"
+        />
+      ),
+    },
+  ];
+
+  // When clean data, set to original values
+  const cleanData = () => {
+    setAvailableOptions(data);
+    setChosenOptions([]);
+  };
+
+  // Clean fields and close modal (To prevent data persistence when reopen modal)
+  const cleanAndCloseModal = () => {
+    cleanData();
+    props.modalData.handleModalToggle();
+  };
+
+  // Buttons are disabled until the user fills the required fields
+  const [buttonDisabled, setButtonDisabled] = useState(true);
+  useEffect(() => {
+    if (chosenOptions.length > 0) {
+      setButtonDisabled(false);
+    } else {
+      setButtonDisabled(true);
+    }
+  }, [chosenOptions]);
+
+  // Get all info from a chosen option
+  const getInfoFromGroupData = (option: unknown) => {
+    const availableDataCopy = [...props.availableData];
+    return availableDataCopy.find((d) => {
+      const name = getNameValue(d);
+      return option === name;
+    });
+  };
+
+  // Add new member to 'User group'
+  const onAddToUserGroup = (toUid: string, newData: string[]) => {
+    addMemberToUserGroup([toUid, newData]).then((response) => {
+      if ("data" in response) {
+        if (response.data.result) {
+          // Set alert: success
+          props.alerts.addAlert(
+            "add-member-success",
+            "Added new members to user group '" + toUid + "'",
+            "success"
+          );
+          // Close modal
+          props.modalData.handleModalToggle();
+        } else if (response.data.error) {
+          // Set alert: error
+          const errorMessage = response.data.error as unknown as ErrorResult;
+          props.alerts.addAlert(
+            "add-member-error",
+            errorMessage.message,
+            "danger"
+          );
+        }
+      }
+    });
+  };
+
+  // Add group option
+  const onClickAddGroupHandler = () => {
+    // List of items to be added
+    const newGroupRepoItems: unknown[] = [...props.groupRepository];
+    const optionsToAdd: string[] = [];
+
+    chosenOptions.map((opt) => {
+      let optionData = getInfoFromGroupData(opt);
+      if (optionData !== undefined) {
+        // User groups
+        if (props.tabData.tabName === "User groups") {
+          optionData = optionData as UserGroupNew;
+          newGroupRepoItems.push({
+            cn: optionData.cn !== undefined && optionData.cn,
+            description:
+              optionData.description !== undefined && optionData.description,
+            gidnumber:
+              optionData.gidnumber !== undefined && optionData.gidnumber,
+          });
+          optionsToAdd.push(optionData.cn);
+        }
+        // Netgroups
+        if (props.tabData.tabName === "Netgroups") {
+          optionData = optionData as Netgroup;
+          props.groupRepository.push({
+            name: optionData.name !== undefined && optionData.name,
+            description:
+              optionData.description !== undefined && optionData.description,
+          } as Netgroup);
+          props.updateGroupRepository(props.groupRepository as Netgroup[]);
+        }
+        // Roles
+        if (props.tabData.tabName === "Roles") {
+          optionData = optionData as Roles;
+          props.groupRepository.push({
+            name: optionData.name !== undefined && optionData.name,
+            description:
+              optionData.description !== undefined && optionData.description,
+          } as Roles);
+          props.updateGroupRepository(props.groupRepository as Roles[]);
+        }
+        // HBAC rules
+        if (props.tabData.tabName === "HBAC rules") {
+          optionData = optionData as HBACRules;
+          props.groupRepository.push({
+            name: optionData.name !== undefined && optionData.name,
+            description:
+              optionData.description !== undefined && optionData.description,
+          } as HBACRules);
+          props.updateGroupRepository(props.groupRepository as HBACRules[]);
+        }
+        // Sudo rules
+        if (props.tabData.tabName === "Sudo rules") {
+          optionData = optionData as SudoRules;
+          props.groupRepository.push({
+            name: optionData.name !== undefined && optionData.name,
+            description:
+              optionData.description !== undefined && optionData.description,
+          } as SudoRules);
+          props.updateGroupRepository(props.groupRepository as SudoRules[]);
+        }
+        // Host groups
+        if (props.tabData.tabName === "Host groups") {
+          optionData = optionData as HostGroup;
+          props.groupRepository.push({
+            name: optionData.name !== undefined && optionData.name,
+            description:
+              optionData.description !== undefined && optionData.description,
+          } as HostGroup);
+          props.updateGroupRepository(props.groupRepository as HostGroup[]);
+        }
+      }
+    });
+
+    // API call
+    onAddToUserGroup(props.tabData.userName, optionsToAdd);
+
+    // Send updated data to table based on data type (New approach)
+    switch (props.tabData.tabName) {
+      case "User groups":
+        props.updateGroupRepository(newGroupRepoItems as UserGroupNew[]);
+        break;
+      // TODO: Add other cases here as they're adapted to the C.L.
+    }
+
+    // Clean chosen options and close modal
+    setChosenOptions([]);
+    props.modalData.handleModalToggle();
+  };
+
+  // Buttons that will be shown at the end of the form
+  const modalActions = [
+    <Button
+      key="add-new-user"
+      variant="secondary"
+      isDisabled={buttonDisabled}
+      form="modal-form"
+      onClick={onClickAddGroupHandler}
+    >
+      Add
+    </Button>,
+    <Button key="cancel-new-user" variant="link" onClick={cleanAndCloseModal}>
+      Cancel
+    </Button>,
+  ];
+
+  // Render 'MemberOfaddModal'
+  return (
+    <ModalWithFormLayout
+      variantType="medium"
+      modalPosition="top"
+      offPosition="76px"
+      title={
+        "Add user '" +
+        props.tabData.userName +
+        "' into " +
+        props.tabData.tabName
+      }
+      formId="is-member-of-add-modal"
+      fields={fields}
+      show={props.modalData.showModal}
+      onClose={cleanAndCloseModal}
+      actions={modalActions}
+    />
+  );
+};
+
+export default MemberOfAddModal;
diff --git a/src/components/MemberOf/MemberOfTableNew.tsx b/src/components/MemberOf/MemberOfTableNew.tsx
index bbcfbb6e3..b0e5a1f4b 100644
--- a/src/components/MemberOf/MemberOfTableNew.tsx
+++ b/src/components/MemberOf/MemberOfTableNew.tsx
@@ -28,7 +28,7 @@ interface ColumnNames {
 // To display all the possible data types for all the tabs (and not only the mandatory ones)
 //   an extra interface 'MemberOfElement' will be defined. This will be called in the 'PropsToTable'
 // //   interface instead of each type (UserGroup | Netgroup | Roles | HBACRules | SudoRules | HostGroup).
-interface MemberOfElement {
+export interface MemberOfElement {
   cn?: string;
   name?: string;
   gid?: string;
diff --git a/src/hooks/useAlerts.tsx b/src/hooks/useAlerts.tsx
index 7fcbca202..ba902428a 100644
--- a/src/hooks/useAlerts.tsx
+++ b/src/hooks/useAlerts.tsx
@@ -15,6 +15,15 @@ export interface AlertInfo {
   variant: AlertVariant;
 }
 
+// In some cases, it is needed to propagate a specific alert to child components.
+// The following object is defined to be refered everytime an Alert is propagated via props.
+export interface AlertObject {
+  addAlert: (name: string, title: string, variant: AlertVariant) => void;
+  removeAlert: (name: string) => void;
+  removeAllAlerts: () => void;
+  ManagedAlerts: () => JSX.Element;
+}
+
 export function useAlerts() {
   const [alerts, setAlerts] = React.useState<AlertInfo[]>([]);
 
diff --git a/src/pages/ActiveUsers/UserMemberOf.tsx b/src/pages/ActiveUsers/UserMemberOf.tsx
index b9efadac9..c219abd30 100644
--- a/src/pages/ActiveUsers/UserMemberOf.tsx
+++ b/src/pages/ActiveUsers/UserMemberOf.tsx
@@ -36,14 +36,21 @@ import {
 // Modals
 import MemberOfAddModal from "src/components/MemberOf/MemberOfAddModal";
 import MemberOfDeleteModal from "src/components/MemberOf/MemberOfDeleteModal";
+import MemberOfAddModalNew from "src/components/MemberOf/MemberOfAddModalNew";
+// RPC
 import { useGetUserByUidQuery } from "src/services/rpc";
+// Hooks
 import { useUserMemberOfData } from "src/hooks/useUserMemberOfData";
+import useAlerts from "src/hooks/useAlerts";
 
 interface PropsToUserMemberOf {
   user: User;
 }
 
 const UserMemberOf = (props: PropsToUserMemberOf) => {
+  // Alerts to show in the UI
+  const alerts = useAlerts();
+
   // Retrieve each group list from Redux:
   let netgroupsList = useAppSelector((state) => state.netgroups.netgroupList);
   let rolesList = useAppSelector((state) => state.roles.roleList);
@@ -51,6 +58,9 @@ const UserMemberOf = (props: PropsToUserMemberOf) => {
   let sudoRulesList = useAppSelector((state) => state.sudorules.sudoRulesList);
 
   // Alter the available options list to keep the state of the recently added / removed items
+  const updateUserGroupsList = (newAvOptionsList: unknown[]) => {
+    setUserGroupsFromUser(newAvOptionsList as UserGroupNew[]);
+  };
   const updateNetgroupsList = (newAvOptionsList: unknown[]) => {
     netgroupsList = newAvOptionsList as Netgroup[];
   };
@@ -71,7 +81,7 @@ const UserMemberOf = (props: PropsToUserMemberOf) => {
 
   const [user, setUser] = React.useState<Partial<User>>({});
 
-  // Member groups associated to user (string[] | UserGroupNew[])
+  // Member groups associated to user
   const [userGroupsFromUser, setUserGroupsFromUser] = React.useState<
     UserGroupNew[]
   >([]);
@@ -118,6 +128,14 @@ const UserMemberOf = (props: PropsToUserMemberOf) => {
   // Filter functions to compare the available data with the data that
   //  the user is already member of. This is done to prevent duplicates
   //  (e.g: adding the same element twice).
+  const filterUserGroupsData = () => {
+    // User groups
+    return userGroupsFullList.filter((item) => {
+      return !userGroupsFromUser.some((itm) => {
+        return item.cn === itm.cn;
+      });
+    });
+  };
   const filterNetgroupsData = () => {
     // Netgroups
     return netgroupsList.filter((item) => {
@@ -152,6 +170,7 @@ const UserMemberOf = (props: PropsToUserMemberOf) => {
   };
 
   // Available data to be added as member of
+  const userGroupsFilteredData: UserGroupNew[] = filterUserGroupsData();
   const netgroupsFilteredData: Netgroup[] = filterNetgroupsData();
   const rolesFilteredData: Roles[] = filterRolesData();
   const hbacRulesFilteredData: HBACRules[] = filterHbacRulesData();
@@ -557,6 +576,7 @@ const UserMemberOf = (props: PropsToUserMemberOf) => {
   // Render 'ActiveUsersIsMemberOf'
   return (
     <>
+      <alerts.ManagedAlerts />
       <Page>
         <PageSection
           variant={PageSectionVariants.light}
@@ -766,6 +786,17 @@ const UserMemberOf = (props: PropsToUserMemberOf) => {
             )}
           </>
         )} */}
+        {showAddModal && (
+          <MemberOfAddModalNew
+            modalData={addModalData}
+            availableData={userGroupsFilteredData}
+            groupRepository={userGroupsFromUser}
+            updateGroupRepository={updateGroupRepository}
+            updateAvOptionsList={updateUserGroupsList}
+            tabData={tabData}
+            alerts={alerts}
+          />
+        )}
         {tabName === "Netgroups" && (
           <>
             {showAddModal && (
diff --git a/src/services/rpc.ts b/src/services/rpc.ts
index 69875f610..39efd6e4d 100644
--- a/src/services/rpc.ts
+++ b/src/services/rpc.ts
@@ -999,6 +999,21 @@ export const api = createApi({
             };
       },
     }),
+    groupAddMember: build.mutation<BatchRPCResponse, [string, string[]]>({
+      query: (payload) => {
+        const toUid = payload[0];
+        const listOfMembers = payload[1];
+        const membersToAdd: Command[] = [];
+        listOfMembers.map((member) => {
+          const payloadItem = {
+            method: "group_add_member",
+            params: [[member], {user: toUid}],
+          } as Command;
+          membersToAdd.push(payloadItem);
+        });
+        return getBatchCommand(membersToAdd, API_VERSION_BACKUP);
+      },
+    }),
   }),
 });
 
@@ -1080,4 +1095,5 @@ export const {
   useGetHostsFullDataQuery,
   useGetUserByUidQuery,
   useGetUserGroupsQuery,
+  useGroupAddMemberMutation,
 } = api;