Generally you setup a page to have a type pf content when it is expecting it.
If from another page a current user clicked on a data type … say in a repeating group … and you need to show the contents of that data type in another page … then you need to set up a page with content of that data type so that it can receive that content when it is “transmitted” by means of the click on that rg row from the origin page.
Think of all of your objects (data types) in your database this way. Only exception is the user data type when he/she are the current user in the app’s session. You do not need to send him/her anywhere because you can access the current user anywhere in Bubble’s front end (thus … not in backend flows).
Hope this makes senses