"Upon further review", this seams to work. Vm is the ViewModel. Level1 is the QueryableDomainServiceCollectionView. This code is in the view codebehind.
I'm getting more than 1 hit on the database however. Perhaps the Rebind is unnecessary?
Can you confirm that this in theory is a reasonable approach? That is, clearing the QDSCV filterdescriptors and adding the TreeListView descriptors to the QDSCV? Is there a better event to be applying this logic?
private void MyTreeList_OnFiltered(object o, GridViewFilteredEventArgs e)
MyTreeList.FilterDescriptors.ToList().ForEach(fd => Vm.Level1.FilterDescriptors.Add(fd));