I have a two polygons, the big one and the small one inside of the big one. Now I want to create the new polygon which is on the average middle between these two (big and small). I have used Erase tool to create just one donate polygon (without the small one in the middle) and to create negative buffer, but that is not a good idea. New polygon should have some mix of geometries between small and big one.
NOTE that these two polygons doesn't have the same geometry.