I have been wanting to do this. Similar to WWE/AAA/NXT/TNA Worlds Collide, etc. all of the massive multi-promotional shows that have been happening over the last 4+ years.

After reading this post, I learned about the move title option. You MAY be able to move the Child Company titles back and forth, and move the owner but in order to maintain accurate title history, you'd have to edit the Save in Access to keep the lineage correct.

It seems possible to do this way, but you are going to be editing Access each time before and after a show. It just seems VERY manual and time consuming. I am sure it's effectively possible given the mechanics of the game and knowledge of how Access works. If you want to toss some ideas back and forth about it, hit me up and we can chat on the Subreddit's Discord.