BuddyPress.org

Since you saved me the time looking for this, I’ll throw in the other 2 I already knew:
groups_is_user_mod( $bp->loggedin_user->id, $bp->groups->current_group->id)
groups_is_user_admin( $bp->loggedin_user->id, $bp->groups->current_group->id)

Plus, that’s the code to get the logged in userid and current groupid.