I try to backup some folders and files with dietpi-backup tools…so I complete include/exclude filter as follows:
So my intention is to copy the contents of /opt/ and /var/www/ and skip everything else. But it doesn’t…it copies everything.
Well this is not the purpose of our backup tool 
Might be better to backup your folders using dietpi-sync or create an own rsync command.
Adding
+ /var/www/
+ /opt/
- /
to the very top of the filter doesn’t work, right? Or - /* instead of - /. Either in general or because / is the backup source, excluding root might not work. And indeed this sounds like a job better suited for dietpi-sync.