Thank you very much for your feedback. Splitting my survey into two surveys and then reconnecting the two via URL is something I've thought of. However, there is a lot of logic in the survey and the second survey would then have to access the logic of the first survey. And that doesn't work, does it?
If I would solve this via templating: getbootstrap.com/docs/4.0/components/progress/
then I would need at least a possibility to adapt the templating to the question groups. So question group 1 has progress bar 1 and question group 2 has progress bar 2. But I didn't find that here:
www.limesurvey.org/manual/Theme_editor
Did I miss something there?
Then the progress bar would only have a display character without logic behind it, but that would not be so bad.
Thanks for your support