You can visit the DriveHQ Service Manual page, look for DriveHQ Online Backup to find more detailed information about Online Backup. Please click the link below about how to restore older version files.
Please note if your file is never changed, then even if it is set to keep 5 versions, you will only have 1 version. If your backup task is set to backup your files at night time, and if you keep changing your file during the day time, the file will not be backed up until at the scheduled time. It will only backup the latest version. If you change the file later then it will be backed up later, then you will have multiple versions of the file.
FYI, DriveHQ.com website and DriveHQ FileManager also supports file versioning. Using DriveHQ FileManager, you can right click on a file and select History to see the file versions.