Files with filegroup file extension may exist. However, at the moment, we do not have any information regarding their origin or purpose.
FILEGROUP file extension - Unknown file extension
What is filegroup file? How to open filegroup files?
File type specification:
The filegroup file extension seems to be in use for certain files that are mentioned on the internet. However, we have not yet found their original program nor any specific information about it.
If you know some more useful informations about the filegroup file extension, please let us know in the discussion below or on our forums.