Not applicable
Have besides the multiselect component, another component that loads its contents dynamically (axios).
Show the select fold-out on top of the other component's results.
As the other component renders last, it will always render on top of the multiselect.
A picture says more than a thousand words...

Z-index (e.g. -10) on result cards.
Result: elements become unclickable as they render behind the parent div
Z-index (e.g. 10) on multiselect__select classes (e.g. active)
Result: works when done in Firefox DOM inspector, but not when applied to code. Which I assume has to do with the later rendering of the results component.
Any ideas?
Wrap the component inside a div with position: relative and some higher z-index.
Most helpful comment
Wrap the component inside a
divwithposition: relativeand some higherz-index.