Hi!
You can use List Shifter: Reverse, Rotate, Swap and ITERATE (Loop) Over Bubble Lists | Now at v1.4: Adds Numeric Option, GET INDEX Action to exponentially increase the way you can work with repeating groups!
A native alternative is to create a state storing lists of text. When a user clicks on a cell add that Data’s Unique ID to the state.
In your RG’s Data Source just add a :filter to check if that data’s Unique ID is not in that state.
But seriously though, List Shifter is worth learning to use.