Beginner on Making lists

Hello Everyone!

Dynamo beginner here. Please advise on how I can correct the Crosshead placement at level 2.

Below is 3d view that I achieved using the dynamo setup and copy and pasting each group.

As you can see, 1 group for each placement of each structure element per pier location. So I made 15 groups.

Then I saw a video using code blocks and lists to simplify inputs

1st run generates correct placements, but at the 2nd run, it will place the crossheads on level 1

Does the Z coordinate input affects the “0” placement of that even if I already specified that I want it on Level 2?