The "initial role" is defined in the AAA profile:
Virtual AP:
SSID Profile
AAA profile
So you would clone your Virtual AP profile and then change the AAA profile in the new Virtual AP:
config t
wlan virtual ap <new virtual AP name>
clone <old virtual ap name>
That would give you a new virtual AP. You would just change the AAA profile under that new Virtual AP and "save as" a different AAA profile. In the new AAA profile, you would then change the initial role. You would then add the new Virtual AP to your new ap-group.
I am sure there is probably an easier way, and I hope that made sense.