I formed a hierarcy using List box TreeView. I want all sub-levels to be summed up (like a pivot table does.) So for 'small' under 'Abrand' I need to see 55. And same for all above and below. sum(cost) doesnt work!
I became convined that this is not possible using Listbox TreeView. here is my logic: its not possible to differenciate between hierarchy levels in expression ( treeView actually doesn't build a hierarchy - its only seperaying text based on delimiters.)
hierarchy() function and pivot tables solved my problem.