The GOG version of DK2 does not have the required folder for setting up new maps as the original version eg C:\Program Files\Bullfrog\Dungeon Keeper 2\Data\editor\maps. So I created a similar file path in the GOG version eg C:\Program Files\GOGcom\Dungeon Keeper 2\Data\editor\maps. I have copied many different player created maps into this folder but am unable to access these in the game.

How do I access these maps in the GOG version?

No answer to this? I'm having the same problem :(

I think they may need to be created using the gog version of the editor.
Try opening up your favorites in the editor and then saving them and loading the resaved version in that map directory.

It could also be that you have not put the maps in that folder correctly.
Be sure that all of the map files are in that folder and not a sub-folder, and that the thumb image is in the sub-folder for thumbs.

FYI... All of the maps i have created work fine in that directory.