Here is a breakdown of the Material layering workflow I used for my Beyond good and Evil Remake project.
The goal was to experiment with these workflows and see how it worked .
https://www.artstation.com/artwork/lROZ6O
https://www.artstation.com/artwork/B36yAr
Here is the Epic documentation
https://docs.unrealengine.com/5.0/en-US/using-material-layers-in-unreal-engine/