How to separate the XYZ channels of textures

So i’m trying to separate the XYZ co-ordinates of textures (might also be doable with separating UVW of the textures), and then recombine them.

I come from blender so my lingo may be a bit off, but this is what i want to recreate, and what it looks like in blender:

I am trying to separate them so that i can round certain values to create a “pixelated” noise map.
The results i am looking for will be able to do something like this:

Split components seems to be a good start, but that is the RGB values of the texture, i feel like i must be missing something here.
I would really appreciate any help i can get, thanks!