Something rotating around something rotating around something else? No. Not with vanilla Half-Life, anyway. SoHL might be able to do it... Maybe.
Simply having an object rotate around something else is easy enough, but to have something then rotating around that... Not so easy.
Unless I've over-complicated your question and all you wanted was a sphere rotating around another sphere. In which case, a func_rotating sphere with an origin brush (block covered in "origin" texture) centered on the other sphere.
Even in that case you could not have the "moon" also rotating on its own axis, but I guess that could be explained away as tidal locking.