While Scrolling in View: Start when Start Exiting, End when End Exiting

Design help Animations & Interactions
1

Hi guys!

I am trying to set up a While Scrolling in View Animation with the requirement:
START when element STARTS EXITING
END when element ENDS EXITING

I cannot figure out how I should set this up, cannot be that difficult, is it?
(atm I cannot share a link for this but I think it´s also quite clear this way)

Thanks in advance!!!
Manuel