diff --git a/tripleo_ansible/ansible_plugins/filter/tripleo_inventory.py b/tripleo_ansible/ansible_plugins/filter/tripleo_inventory.py
index 478eff05e..4353bff82 100644
--- a/tripleo_ansible/ansible_plugins/filter/tripleo_inventory.py
+++ b/tripleo_ansible/ansible_plugins/filter/tripleo_inventory.py
@@ -50,6 +50,36 @@ def to_inventory_hostmap(data):
     return group_host_map
 
 
+def to_inventory_rolemap(data):
+    # Falttens inventory to a group->role mapping
+    if isinstance(data, six.string_types):
+        inventory = yaml.safe_load(data)
+    else:
+        inventory = data
+
+    group_role_map = {}
+
+    todo = collections.deque(inventory.keys())
+    while todo:
+        group = todo.popleft()
+        if 'tripleo_role_name' in inventory[group].get('vars', {}):
+            group_role_map[group] = [inventory[group]['vars']['tripleo_role_name']]
+        else:
+            if 'children' in inventory[group]:
+                for child in inventory[group]['children']:
+                    # Children have not all been flattened yet
+                    # so postpone flattening this group
+                    if child in todo:
+                        todo.append(group)
+                        break
+                else:
+                    group_role_map[group] = []
+                    for child in inventory[group]['children']:
+                        group_role_map[group] += group_role_map[child]
+                    group_role_map[group].sort()
+    return group_role_map
+
+
 def to_inventory_roles(data):
     # Returns list of tripleo roles in inventory
     if isinstance(data, six.string_types):
@@ -69,5 +99,6 @@ class FilterModule(object):
     def filters(self):
         return {
             'to_inventory_hostmap': to_inventory_hostmap,
+            'to_inventory_rolemap': to_inventory_rolemap,
             'to_inventory_roles': to_inventory_roles,
         }
diff --git a/tripleo_ansible/tests/plugins/filter/test_tripleo_inventory.py b/tripleo_ansible/tests/plugins/filter/test_tripleo_inventory.py
index 6216df688..457b3ec2a 100644
--- a/tripleo_ansible/tests/plugins/filter/test_tripleo_inventory.py
+++ b/tripleo_ansible/tests/plugins/filter/test_tripleo_inventory.py
@@ -28,11 +28,17 @@ allovercloud:
     Controller: {}
   vars: {}
 Controller:
+  children:
+    overcloud_Controller: {}
+overcloud_Controller:
   hosts:
     overcloud-controller-0: {foo_bar: baz}
   vars:
     tripleo_role_name: Controller
 Compute:
+  children:
+    overcloud_Compute: {}
+overcloud_Compute:
   hosts:
     overcloud-novacompute-0: {foo_bar: baz}
   vars:
@@ -49,10 +55,16 @@ dynamic_inventory = """
     "vars" : {}
   },
   "Controller" : {
+    "children": [ "overcloud_Controller" ]
+  },
+  "overcloud_Controller" : {
     "hosts": [ "overcloud-controller-0" ],
     "vars": { "tripleo_role_name": "Controller" }
   },
   "Compute" : {
+    "children": [ "overcloud_Compute" ]
+  },
+  "overcloud_Compute" : {
     "hosts": ["overcloud-novacompute-0" ],
     "vars": { "tripleo_role_name": "Compute" }
   }
@@ -68,7 +80,9 @@ class TestInventoryFilters(tests_base.TestCase):
     def _test_hostmap(self, inventory):
         expected = {
           "Compute": ["overcloud-novacompute-0"],
+          "overcloud_Compute": ["overcloud-novacompute-0"],
           "Controller": ["overcloud-controller-0"],
+          "overcloud_Controller": ["overcloud-controller-0"],
           "overcloud": ["overcloud-controller-0", "overcloud-novacompute-0"],
           "allovercloud": ["overcloud-controller-0", "overcloud-novacompute-0"],
         }
@@ -81,6 +95,24 @@ class TestInventoryFilters(tests_base.TestCase):
     def test_hostmap_dynamic(self):
         self._test_hostmap(dynamic_inventory)
 
+    def _test_rolemap(self, inventory):
+        expected = {
+          "overcloud": ["Compute", "Controller"],
+          "allovercloud": ["Compute", "Controller"],
+          "Controller": ["Controller"],
+          "overcloud_Controller": ["Controller"],
+          "Compute": ["Compute"],
+          "overcloud_Compute": ["Compute"]
+        }
+        result = tripleo_inventory.to_inventory_rolemap(inventory)
+        self.assertEqual(expected, result)
+
+    def test_rolemap_static(self):
+        self._test_rolemap(static_inventory)
+
+    def test_rolemap_dynamic(self):
+        self._test_rolemap(dynamic_inventory)
+
     def _test_roles(self, inventory):
         expected = ["Compute", "Controller"]
         result = tripleo_inventory.to_inventory_roles(inventory)