Terrain Geometry Brush ?

Tried looking how to do this but failing miserably, anyone know how to do this ? …

Have you looked into

I did have a look but not sure what I’m looking for. These work with the terrain ?

If your wondering the texture for the terrain is a landscape material you would have to set the different textures so you get the rock look when it becomes a slope, as for the tools the road is the spline tool Hope that helps some what.