HI, I am Dave, I will help you with this.
Please provide some more detail on this, an .mmap file is a rare file type, usually associated to mind mapping software, where exactly was that file stored on your PC and what software do you use to open that file type
Did you check in your Recycle Bin to see if the file is in there, or on OneDrive online if you use OneDrive to sync your files online.