Gh_Beginner needs help:)!

Hi,
I struggle hard to get my definiton which works on a surface - to get to work on multiple Surfaces at once. I am pretty sure you could help  me out easily as you seem to  be all pros :)!

when i use the GH defintion just on one surface it works out perfectly fine..
But when i try to do that on multiple Surfaces at once - it gets messy and doesn t work at all!

my definition is kinda messy - could clean it up and load it up if its needed for help!

Thanks a lot ! tried to hours to figure a way to solve this.. but failed.