diff --git a/xml_converter/src/string_hierarchy.cpp b/xml_converter/src/string_hierarchy.cpp
index 0c907c39..f14fe51b 100644
--- a/xml_converter/src/string_hierarchy.cpp
+++ b/xml_converter/src/string_hierarchy.cpp
@@ -2,6 +2,24 @@
 
 #include <iostream>
 
+////////////////////////////////////////////////////////////////////////////////
+// in_hierarchy
+//
+// Returns if a particular node exists at the top level of the hirearchy.
+////////////////////////////////////////////////////////////////////////////////
+bool StringHierarchy::in_hierarchy(
+    const std::string &node) const {
+    if (this->all_children_included) {
+        return true;
+    }
+
+    auto iterator = this->children.find(node);
+    if (iterator == this->children.end()) {
+        return false;
+    }
+    return true;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // in_hierarchy
 //
@@ -12,6 +30,19 @@ bool StringHierarchy::in_hierarchy(
     return this->_in_hierarchy(path, 0);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// in_hierarchy
+//
+// An explicit version of in_hierarchy that takes an initalizer list to prevent
+// ambiguity between the vector and string overloads of the function.
+////////////////////////////////////////////////////////////////////////////////
+bool StringHierarchy::in_hierarchy(
+    const std::initializer_list<std::string> &input) const {
+    std::vector<std::string> vec;
+    vec.insert(vec.end(), input.begin(), input.end());
+    return this->in_hierarchy(vec);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // _in_hirearchy
 //
@@ -39,6 +70,57 @@ bool StringHierarchy::_in_hierarchy(
     return iterator->second._in_hierarchy(path, continue_index + 1);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// sub_hierarchy
+//
+// A helper function to grab a sub hierarchy one level down from the top.
+////////////////////////////////////////////////////////////////////////////////
+const StringHierarchy *StringHierarchy::sub_hierarchy(
+    const std::string &node) const {
+    if (this->all_children_included) {
+        return this;
+    }
+
+    auto iterator = this->children.find(node);
+    if (iterator == this->children.end()) {
+        return nullptr;
+    }
+    return &(iterator->second);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// sub_hierarchy
+//
+// An explicit version of sub_hierarchy that takes an initalizer list to
+// prevent ambiguity between the vector and string overloads of the function.
+////////////////////////////////////////////////////////////////////////////////
+const StringHierarchy *StringHierarchy::sub_hierarchy(
+    const std::initializer_list<std::string> &input) const {
+    std::vector<std::string> vec;
+    vec.insert(vec.end(), input.begin(), input.end());
+    return this->sub_hierarchy(vec);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// sub_hierarchy
+//
+// Get a subtree of the StringHierarchy in order to avoid needing to query the
+// entire hierarchy in the case where the use case is traversing down a tree
+// anyways and does not want to keep track of the parent's values.
+////////////////////////////////////////////////////////////////////////////////
+const StringHierarchy *StringHierarchy::sub_hierarchy(
+    const std::vector<std::string> &path) const {
+    const StringHierarchy *sub_hierarchy = this;
+    for (size_t i = 0; i < path.size(); i++) {
+        sub_hierarchy = sub_hierarchy->sub_hierarchy(path[i]);
+        // Escape before segfaulting.
+        if (sub_hierarchy == nullptr) {
+            return nullptr;
+        }
+    }
+    return sub_hierarchy;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // add_path
 //
diff --git a/xml_converter/src/string_hierarchy.hpp b/xml_converter/src/string_hierarchy.hpp
index 9a5587db..594300ba 100644
--- a/xml_converter/src/string_hierarchy.hpp
+++ b/xml_converter/src/string_hierarchy.hpp
@@ -7,6 +7,21 @@
 class StringHierarchy {
  public:
     bool in_hierarchy(
+        const std::string &node) const;
+
+    bool in_hierarchy(
+        const std::vector<std::string> &path) const;
+
+    bool in_hierarchy(
+        const std::initializer_list<std::string> &input) const;
+
+    const StringHierarchy *sub_hierarchy(
+        const std::string &node) const;
+
+    const StringHierarchy *sub_hierarchy(
+        const std::initializer_list<std::string> &input) const;
+
+    const StringHierarchy *sub_hierarchy(
         const std::vector<std::string> &path) const;
 
     void add_path(
diff --git a/xml_converter/tests/test_string_hierarchy.cpp b/xml_converter/tests/test_string_hierarchy.cpp
index 7eed8a30..4e2d84c8 100644
--- a/xml_converter/tests/test_string_hierarchy.cpp
+++ b/xml_converter/tests/test_string_hierarchy.cpp
@@ -18,6 +18,11 @@ TEST_F(StringHierarchyTest, BasicPath) {
     EXPECT_TRUE(string_hierarchy.in_hierarchy({"root", "child1", "child2"}));
 }
 
+TEST_F(StringHierarchyTest, BasicPathSingle) {
+    string_hierarchy.add_path({"root", "child1", "child2"}, false);
+    EXPECT_TRUE(string_hierarchy.in_hierarchy("root"));
+}
+
 TEST_F(StringHierarchyTest, ParentPath) {
     string_hierarchy.add_path({"root", "child1", "child2"}, false);
     EXPECT_TRUE(string_hierarchy.in_hierarchy({"root", "child1"}));
@@ -34,6 +39,11 @@ TEST_F(StringHierarchyTest, InvalidRoot) {
     EXPECT_FALSE(string_hierarchy.in_hierarchy({"badroot"}));
 }
 
+TEST_F(StringHierarchyTest, InvalidRootSingle) {
+    string_hierarchy.add_path({"root", "child1", "child2"}, false);
+    EXPECT_FALSE(string_hierarchy.in_hierarchy("badroot"));
+}
+
 TEST_F(StringHierarchyTest, NonExistantDepthNode) {
     string_hierarchy.add_path({"root", "child1", "child2"}, false);
     EXPECT_FALSE(string_hierarchy.in_hierarchy({"root", "child1", "child2", "child3"}));
@@ -67,6 +77,41 @@ TEST_F(StringHierarchyTest, AllowAll) {
     EXPECT_TRUE(string_hierarchy.in_hierarchy({"literally", "anything"}));
 }
 
+TEST_F(StringHierarchyTest, AllowAllSingle) {
+    string_hierarchy.add_path({}, true);
+    EXPECT_TRUE(string_hierarchy.in_hierarchy("everything"));
+}
+
+TEST_F(StringHierarchyTest, InvalidHierarchy) {
+    string_hierarchy.add_path({"root", "child1", "child2"}, false);
+    const StringHierarchy* sub_hierarchy = string_hierarchy.sub_hierarchy({"invalid"});
+    EXPECT_EQ(sub_hierarchy, nullptr);
+}
+
+TEST_F(StringHierarchyTest, SubHierarchy) {
+    string_hierarchy.add_path({"root", "child1", "child2"}, false);
+    const StringHierarchy* sub_hierarchy = string_hierarchy.sub_hierarchy({"root", "child1"});
+    EXPECT_NE(sub_hierarchy, nullptr);
+    EXPECT_FALSE(sub_hierarchy->in_hierarchy("root"));
+    EXPECT_FALSE(sub_hierarchy->in_hierarchy("child1"));
+    EXPECT_TRUE(sub_hierarchy->in_hierarchy("child2"));
+}
+
+TEST_F(StringHierarchyTest, InvalidDeepHierarchy) {
+    string_hierarchy.add_path({"root", "child1", "child2"}, false);
+    const StringHierarchy* sub_hierarchy = string_hierarchy.sub_hierarchy({"invalid", "nonexistant"});
+    EXPECT_EQ(sub_hierarchy, nullptr);
+}
+
+TEST_F(StringHierarchyTest, SubHierarchySingle) {
+    string_hierarchy.add_path({"root", "child1", "child2"}, false);
+    const StringHierarchy* sub_hierarchy = string_hierarchy.sub_hierarchy("root");
+    EXPECT_NE(sub_hierarchy, nullptr);
+    EXPECT_FALSE(sub_hierarchy->in_hierarchy("root"));
+    EXPECT_TRUE(sub_hierarchy->in_hierarchy("child1"));
+    EXPECT_TRUE(sub_hierarchy->in_hierarchy({"child1", "child2"}));
+}
+
 int main(int argc, char **argv) {
     ::testing::InitGoogleTest(&argc, argv);
     return RUN_ALL_TESTS();