How to automatically assign "other groups" to new users in Workfront Fusion?

Background: new users are created by submitting a request which automatically creates the user with necessary permissions/groups/teams/etc.

Issue: I'm able to assign a Home Group up user creation, but not Other Groups (i.e. they've been assigned to the global group, but not the regional group).  

I've tried the Update Record module > User record type however Other Groups doesn't appear as a mappable field. I've also tried Update Record > Group as well, however add members doesn't appear there as well. 

Is there a way to assign other groups to users created via Workfront Fusion automation?