Only one parent group?

This is a serious limitation for our requirements =( We definitely need the ability for groups to have multiple parents. We are a large institution with thousands of users and groups. Just wondering if anyone sees this as a limitation too.

I was looking through the code and database tables. Unfortunately adding multiple parent groups would be a significant modification.

My suggestions to the author:
1) I would change the groups_user_group table which maps users to groups (or vice versa). Instead I would make it more flexible… groups_group_mapping table which maps a group_id to member_id which can be a group or user. The table would look like this
group_id bigint
member_id bigint
member_type tinyint (e.g. 0 = user, 1 = group)

Doing that change will allow groups to contain multiple groups and users as members. Of course it complicates the logic in determining membership because of recursion (and avoiding circular loops).
2) If you did #1 then you would not need groups_group.parent_id anymore

Just something to think about. Excellent plugin in general.

http://ww.wp.xz.cn/plugins/groups/