Hi Ralf.
Here are two possibilities that come to my mind quickly:
- Use features of our addon Popover (!) from SPPB Pro 5.x - easy way - watch video in blog post: https://www.joomshaper.com/blog/sp-page-builder-v5-1-4
- Use Online generator for Image Map where you can upload image and add active points and it will generate you code similar to that:
<img src="/images/ship.jpg" usemap="#image-map" alt="SHIP">
<map name="image-map">
<area target="" alt="" title="" href="#dot1" coords="6,230,119,5" shape="rect">
<area target="" alt="" title="" href="#dot2" coords="234,230,124,5" shape="rect">
<area target="" alt="" title="" href="#dot3" coords="347,230,239,5" shape="rect">
(...)
</map>
Which later you have to paste into Raw HTML addon.
But using it as background image + buttons - does not make sense, too problematic as you noticed