Your material is quite complicated and is missing a lot of textures.
So, here are two examples of how parallax can be used in a node material:
- Standard material: Babylon.js Node Material Editor
- PBR material: https://playground.babylonjs.com/#NSG82E#8 (forum thread: Is there the way to use Parallax Mapping for node material? - #37 by Evgeni_Popov)