You can create a new map based on an XMind or XMind: ZEN file. MindManager supports XMind 8 update 7 files and XMind: ZEN files
Click the File tab, click Import, and then click Import XMind File.
In the Choose Location dialog, do one of the following:
To import a file on your system, choose Local.
To import a file stored in a cloud storage service, choose the service.
In the dialog, select the XMind or XMind: Zen file to import. The XMind or XMind: ZEN map file extension is .xmind.
Click Open.
Click the File tab, click Open.
Navigate to the folder that contains the XMind or XMind: ZEN file.
In the list box next to the File name box, choose XMind Map File (*.xmind).
Select the XMind or XMind: ZEN map file.
Click Open.