Howdy bandoliergroup,
That’s a good question. One user in a similar situation had success using theĀ post duplicator plugin, instead of inputting the info multiple times they just duplicated it, then edited it to include custom info (like the event venue).
If you are interested in adding the exact functionality you want via some PHP/MySQL magic, you could hook into ‘pre_get_posts‘ and add the necessary logic there. Maybe detect a custom Venue Name, like “all-venues” or something, then simply include venues with that name in all tribe queries regardless of the venue specified. Does that make sense?
Please let me know if that helps, or if you have any more questions. Cheers!
– Brook