We have no feature to do this. You'd need to somehow configure CB Auto Actions for it is my best guess. However there's a problem with doing this; performance. Lets say you've 1,000 users. When a user registers that's something like 2,000 queries and 1,000 PHP calls to connect to all of them and that's just for 1 registration. Lets say 5 users register at once. The math exponentially gets worse the more users you have.
The most performance optimized way to do it would be a single database query, but that won't fire any CB triggers or send any notifications. The below query should do what you're wanting and can be used in CB Auto Actions with the Query action on the after registration trigger.
Code:
INSERT INTO `#__comprofiler_members` ( `referenceid`, `memberid`, `accepted`, `pending`, `membersince` ) VALUES ( SELECT '[user_id]', `id`, 1, 0, NOW() FROM `#__users` WHERE `id` != '[user_id]' )
Please note I did not test the above query. Please be sure to test thoroughly and adjust as needed.
krileon
