The supplied source exposes several auxiliary terrain resources and maintenance tools rather than a single “ground details” brush.

previews the current noise map and supports PNG import, PNG export and inversion. The Country Editor can overlay this map in its country preview.
provides the same import/export/invert workflow for the coastline bump resource.
The Tools menu can open read-only viewers for the small bump texture and sky texture.
recomputes landscape shadow information. Sculpt operations also update shadows for blocks changed by the stroke.