Hi there! In this case my head model is far away from center and NanoMesh is far away from head. The question is how to have them zoomed in both windows?
in the case the nanomesh will line up with the surface and not the whole subtools volume, which that can offset, the position in split screen mode.
so what you can do is to edit mesh, and go to tool :size: XYZ size, and change from 2.0 ( a value that ZBrush uses to scale thing, so it works better for example with dynameshing etc.
but in my test I had to reduce the size from 2.0 to 0.25, then i get off the edit mesh mode, and change the size directly in that panel.
before :
after :
Hope it helps!
Nicolas