An answer on this question ist definitly interesting me too!
In the documentation it says the suggestionbox is multicolumn-able, but how about the list that drops down, when clicking on the arrow?
many thanks in advance
Combox has no such feature. In this simple component select like usage was a main goal at design stage. So it doesn't works with columns.
We plan to provide JS API for calling suggestions for suggestion component. So user defined "arrows" usage will be possible and multycolumn feature will be available from this component. Just explore our wiki future page and vote for features you need.