hello, I am having trouble with this node not working when only a single element is selected because it changes the list structure. It works fine in multiselection mode but when only one element is select it breaks down. i need a way to find all of the indicies of the markers so i can filter out all the appropriate elements, but it doenst work. Any ideas @erfajo? 
Try creating a list from your selected element(s) then flattening it. That way you always have a singular list to check.
yeah I have been successful using this node at levels. I found a work around by simply replacing nulls with 0 and that solves the problem since it only is a problem when my selection has only one element and therefore messes up the list structure. Its admittately sloppy, but unless someone can point out some reason that this wouldnt work that I am not seeing I am going to stick with this.
