Material Layer Change per Terrain Slope

should do it:

.unrealengine.com/latest/INT/Engine/Rendering/Materials/Functions/Reference/Texturing/index.html#worldcoordinate3way

Try setting up a rotator node with a parameter and tweak the sides until they look right- way you can use the same texture.

EDIT- didn’t realize it used texture objects I’m not sure how to rotate them, if anyone knows how I’d love to know as well.