Let me get this straight. You have a backup made with BackupMenu and want to restore your phone to that backup using Fasher? The short answer is you can't. BackupMenu uses the tar format and Flasher uses its own format which is almost, but not entirely unlike tar. Someone might be able to write a convertor but you can't just take one and expect it to work in the other.

There is a way of restoring a BackupMenu backup without using BackupMenu but it not for the feint of heart, does not work in all cases, requires a correctly booting device and is so fraught with danger that I would not recommend it to anyone whose Linux skills are below at least a brown belt level.

Why can't you just use BackupMenu?