Hi Rex,
My impression is that you're looking for some ways to automatically select the region of interest to extract x, y, z of nodes (as opposed to manually selecting the region).
This should be possible through scripting in LS-PrePost. I have not tried this, but I found the course below that might be of help to you. The course is on Ansys Learning Hub (requires subscription). You should be able to access more resources if you look up LS-PrePost Scripting online.

LS-DYNA | Advanced Practices - Ansys LS-PrePost Advanced (