Now I need advanced skills related to landscape materials.

I need some advanced techniques for Unreal Engine landscape materials now. I’m building materials for a golf course, and I already know how to do layer blending and runtime virtual texturing, so please exclude those. What I need is to make the landscape receive light more strongly depending on its normal (meaning the terrain’s curvature/slope, not the texture normal). You could call it subsurface color. But I don’t know how to implement this. For reference, I’m talking about the highlighted areas in this image.