Hello Dr. Watson,
as far as I know there is no way to copy a map. But you can move the map in the Sites-Tree View.
Do to that select the map you want to move in the tree view. Select "File->Properties" in the right window. Press the tree symbol on the right sight of "Parent map" and select the map you want to add the "moved" map.
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Regards
Stephan
Regards
Stephan