How to apply node displacement to geo / how to stick object to the ground?

Hello, I am trying displacement workflow in Blender and stuck with two issues:

  1. How to apply displacement to geo that I used in shader editor for cycles render? Displacement modifier won’t help here because I mingled several displacement maps and changed texture coordinates.
  2. How to stick objects to surface with displacement? I have some items lying on the plane, but displacement changes geo and objects begun floating in the air or sunk in the ground.
    Thank you in advance.

Displacement in the node editors are there just to pretend there is a geometry. So if you want to stick other objects onto the surface that is made by displacement, you need to use modifier and apply that change to make a real geometry.