Thanks for quick feedback, Juergen.
It seems to be very different on my Android 5.1 Nexus 6.
When I do Menu->Data->Backup, I don't have any option of chosing a directory or changing the filename. It just says immediately "Data backup to SD completed." I cannot find that backup file anywhere in my Internal Storage. Theres nothing in my tasker folder except 3 empty subfolders: .icn, cache and userguide. Certainly no Tasker/configs/user path anywhere. Yes, hidden items and system files are set visible.
Also, no Tasker/configs/auto folder anywhere. So auto-backups also seems useless.
How can I spot that backup file to copy it to my computer?
regards,
Robert