Add a compound group sync filter

Zendesk: https://gitlab.zendesk.com/agent/tickets/22546

A customer noted that it would be great if they could optionally specify a compound group filter for group sync. For example, instead of just saying 'group X should be synced' users would be able to say 'users should be synced if they are a member of group X and Y'. I'm not sure of the best way to implement this or if we should, but let's discuss it and see how it would work.