You can paste a surface into the current surface. For example, if you have a building pad surface, you can paste it into a full-site surface. The building pad replaces that portion of the site surface that it covers.
When the surface is pasted into the existing surface, the command adjusts the overlapping area to the elevation and contouring of the pasted surface.
The operation is added as a Paste Surface item to the Edits list view in Prospector.