The Cobotta Base Plate comes with an upper (smaller) and lower (larger) section. Since the Cobotta has its screw mounting holes on the bottom of the base, it is intended that the upper part of the base screw into the Cobotta from the bottom up. With the upper base attached to the Cobotta, the complete assembly can then be screwed from the top down onto the lower base. The screws of the upper base will be hidden once the two pieces are attached.
For additional explanation please reference the Cobotta user manuals here: