Hi Don,
Thank you very much.
Well, unfortunately this is not a z-index issue, but an overflow problem. The section container has an invisible overflow set, which means, that none of the containing element can be visible outside the container boundaries, see: https://i.imgur.com/Fukn5zX.png
This is not possible to bypass in any way. The only exceptions are fixed positioned elements, but in this case tit’s not applicable.
I am not sure what is the best resolution here. The overfolw I guess is needed for the parallax effect. Maybe instead of searchable multiselect, using a checkbox layout could work, as it has a fixed height, and no floating elements.