Stacking of elements

Hi community

Quite new to Principle but understand the tool quite well. Nevertheless, even as I know the key is the drivers for the following, I don’t know how to solve this.

I want to have elements that stack for a while while scrolling until another element pushes them away. Here is a demo

stack

Hope somebody knows a solution.
Thanks a lot upfront.

Ps.: Here is a stacking doc in Principle I made. It works but I would like to know, how to make it using the inspectors and not “faking” it.