Jill,
This is possible using an EXISTS filter within a User Report. You'll want to switch to text mode and replace ID HERE with the ID of the specific group. This will pull in a list of all active users who do not have that group listed as either their Home Team or under Other Teams.
EXISTS:A:$$EXISTSMOD=NOTEXISTS
EXISTS:A:$$OBJCODE=USRGPS
EXISTS:A:groupID=ID HERE
EXISTS:A:userID=FIELD:ID
isActive=true
isActive_Mod=eq
If this wasn't exactly what you were looking for, or have additional questions, let me know!
Nichole