BuddyPress.org

Hi, to my understanding currently when installing Buddypress on a multisite subdomain installation groups that are hidden or private on one subdomain are public on another subdomain by default. Can someone help me see the logic or could this be changed for future releases? If I have a hidden group should it not be hidden on all subdomains as that is the purpose otherwise I would make them public. Is this difficult to implement or not the intention of Buddypress?