Today found another neat function in MindManager. I had done each of my AU Session notes as a separate Map linked to an Index Map. I commonly use this when a map grows too large to be easily edited or viewed.
You can easily break a map into separate maps using File>Send To>MindManager (as new Map). This moves the selected topic branch to a new map and creates a hyperlink to the new map file in the source file. You end up with a map that acts as an index for other maps. In the Multimap view below Map1 has five topic maps linked to it.
What I found today was you can easily combine a set of linked maps into one "super" map using the Multimap View's Combine All option.
Map 1 and its five topics merged into one supermap.