Views Contextual Filter allowing consolidated report of Group and SubGroup Contents

Our use case involves creating a consolidated report of group content from both the parent group and child groups. We would like to do this using a View with a contextual filter. The most common use case is a user report.

Given a group with subgroups:

Group_1
  +---[User_Relation]---User1
  +---[User_Relation]---User2
  +---[Subgroup_Relation]---Group_1.1
                              +---[User_Relation]---User3 
                              +---[User_Relation]---User4 
  +---[Subgroup_Relation]---Group_1.2
                              +---[User_Relation]---User5 
                              +---[User_Relation]---User6 
 

The View would be:

/group/%group/consolidated-users

User   Group
-----  ---------
User1  Group_1
User2  Group_1
User3  Group_1.1
User4  Group_1.1
User5  Group_1.2
User6  Group_1.2

After reviewing the avilable filters and relationships I haven't found a way of doing this, so I believe this is a feature request. If this is incorrect, please change to a Support Request. Thanks!