@KPD hard to say of a direct resource for it. Try searching "parallax" in godotshaders. I used this https://godotshaders.com/shader/parallax-ice-for-fake-depth-to-plane-meshes/ as reference, but it's for an older version. What mine does is basically what this one does but within a for loop for your set amount of layers.
I'll release this on godotshaders once I'm finished though!