Specify Subject Sources for Grouper UI (Web)

For the Grouper UI (Web) I'd like to be able to specify subject sources as the default.  If someone wanted to then go and specify a subject source not in the default list, they can use the UI to do so.  By default, for me, I would want to specify g:gsa and my main subject source which has all active users.  This will allow me to add other subject sources like some inactive users and other specialty accounts not normally seen by my users.

THANK YOU!