Linking organic groups - or am I overlooking a better solution? I'm attempting to use Drupal 7 with organic groups to create a network of groups for local affiliates of a national organization. Initially we want users in each group to be able to post private content inside of the group, which is not a problem. However, since local affiliates tend to share ideas and files we'd also like a group administrator to be able to "link" their group with another trusted affiliate so that users of the two affiliates can have access to the content in the linked groups.

I realize the people in each group can be added to other existing groups, but as far as I am aware this is on an individual basis and thus would not be sustainable going forward as members that are added and removed from their primary group would not automatically have their membership changed in the other affiliated groups.

The closest thing I've seen is http://drupal.org/project/og_affiliations but it's no longer being updated. I was wondering if anyone has any ideas for approaching this setup or if there might be a better solution than OG that I'm overlooking?
I have not played around with og much but from what you are saying this should be possible with rules. Basically you would create an event based on the change (perhaps create a group admin role only flag which lets them flag each other to create the bond and the trigger. That way if one breaks the bond, the permissions are reversed which would require an extra but similar rule) that would trigger an action to load a list of users from the group. Then add a loop to loop through the list of users performing an action on each one as you go (i.e. add to other group). Not sure what custom actions og brings to rules or vice versa but I see no reason why it shouldnt be possible this way.