The maximum file path length depend on Windows OS limitation, in case of Windows NTFS, the maximum file path length is 32,767.
Windows can't create paths more than 256 bytes through Windows Explorer, though NTFS has higher limit. BESR/SSR can create long paths programmatically using "\\?\" prefix; Windows Explorer, however, can't access it.
With respect to BESR\SSR :
1) FileFolder backup: Max path limitation for folder backup destination is 210 bytes. Once backup destination is provided, file folder backup creates subdirectory structure within which adds another 46 bytes.
2) VolumeBackup: Max path limitation for Volume backup destination + filename is 256 bytes (including create unique folder option).
The respective max-path validations are present in BESR-UI while configuring volume/file-folder job.