code: GroupIds getGroupIds(Node groupNode) throws RepositoryException
     {
        String storagePath = getGroupStoragePath();
        String nodePath = groupNode.getPath();
  
        String groupId = nodePath.substring(storagePath.length());
        String parentId = groupId.substring(0, groupId.lastIndexOf("/"));
  
        return new GroupIds(groupId, parentId);
     }
docs: Evaluate the group identifier and parent group identifier based on group node path.