If you downloaded "xMoVe" from the App Store from Apple, you have no direct access to the database file. Therefore you are not able to use it on several computers.
Do you want to use these functions, you have to switch to "Mac-MoVe". First, you must export the database. Then you install "Mac-MoVe". After the first start, select the exported database file.
If you worked with "Mac-MoVe" and wants to work "xMoVe", you must import the database. With this function, the current database file is copied to the so-called sandbox of macOS. The old database will not be used any more. You can delete it now.