how to clone shapes across layers

Hello,

maybe I have had the wrong search query keywords, but I cannot figure out how to do the following:

I would like to have shapes on a shape layer,

and would like to clone those onto another layer to add stuff like path operations.

(So to have one copy of the original shapes, and one with, for example, rounded corners.)

BUT if I need to change or animate the shape paths, I only want to do this on one layer - and have the changes automatically carried over to the other one.

Any easy way to do this?

Thank you very much in advance!