Building a banded landscape material to help sculpting

I am trying to create a material to make sculpting landscape easier. The material should add bands to the landscape with it’s height (look at pictures).
I have already made the material which applies the bands to the landscape. The material need min and max height of landscape as parameters to work correctly. However I have no clue how to get these values. I made a Editor Utility Blueprint attempting to get these values from bounds of the landscape actor, but they both returned zero, probably because landscape is world partition (material applies correctly on any other actor but landscape)
I tried applying the material to a single landscape proxy, it kind of did work but it only get the min and max for that single landscape proxy.

  1. How can I get the min and max for the entire lanscape
  2. If I’m doing it wrong, what is the correct way?