How do we compare density profiles when interfaces are not located at the same position in the box?

Dear All,

I have four systems with polymer-water interfaces. I want to check how the density profiles of water change (at the interface and inside the polymer) in four structures. However, the polymer-water interface is positioned in the box differently in each structure; thus, comparing density profiles is complicated. Can anyone know how to fix this issue and make a graph with four density profiles for easy comparison?

Thank you.

Best regards
Amali