Is it possible to Set Up "List of Favorites" with a combination of 3 factors?

Hi,
I am doing an app for a festival, but it can be applicable for conferences as well.
My question is it possible to collect favorites from several locations in 1 TAB.
Here is an illustration what I mean.
First screen is a tab with all stages, next screen is a single stage, where I can select my favorite slots.
I would love to be able to connect next screen (single stage) with the home tab. And more important be able to generate an aggregated list of favorites.

Any advice, tips and hacks are very welcome!
Thanks in advance.
Here is a spreadsheet:


and the app itself - https://mps-bueckeburg.glideapp.io![image0%20(3)|666x500]