How to refresh data in a repeating group when another element is modified

The data in the repeating group(1) comes from an action performed in another repeating group(2),

So I cannot simply create a new workflow when element’s value is changed —> display list in repeating group(2) because I cannot figure out what was the element the user performed an action on in group(1), that defined the datas in group(2)

I would really just like to refresh the data in group(2)… is it possible?

I hope it was understandable… Thanks a lot