We migrated controls from 2007 vol. 3 to 2008 vol. 1 and now it's possible to select nodes from different levels. I think that it should be an option, not default behaviour, because it changes UI a lot! Anyway, I try to disable it, but I don't know how to do it. SelectionBehaviour is set to "UseOverride" and SelectionType is set to "ExtendedAutoDrag".

I want to make it work like before migration: it's possible to select many nodes, but only from one level. How to do it? What values I should set to the properties?