What would be great here regarding social groups is to treat them like categories so they would be available for selection in a drop down list. You would however need to drop downs (or one that is dynamic). One would filter the Role Group and the next would be the specific Role.

On the main views of the calendar like you can filter categories it would then be great to be able to filter any groups that are used on that calendar instance.

 What I will look at for feasibility is being able to add the calendar to a group page in this first pass. The complexity you are looking for here is not something I will investigate initially. We have some other goals in mind for this next release so there is no guarantee that group support will get included. Sorry, too much work, too little time....