r.a.d.treeview supports multiple-select mode, which allows you to select more than one node at once. You can enable multiple-select mode by setting the MultipleSelect property to "True". The end-user will then be able to select more than one node by holding down the Ctrl key while clicking on nodes.

You can retrieve the set of selected nodes upon postback by using the GetSelectedNodes method, which returns an ArrayList of the nodes that had been selected.