By default the CollectionSource's filter criteria are applied to root objects only. Child objects are obtained from the ITreeNode.Children member. This collection is not related to the original collection source and thus is not filtered.
Currently, you can use the following solutions to filter all nodes:
1. Use platform-dependent solutions for the WinForms TreeList and ASP.NET ASPxTreeList controls. To do this, implement a ViewController to access the TreeListEditor or ASPxTreeListEditor objects and customize underlying tree lists to find and focus the required nodes. See the How to search and focus nodes in the Tree List editor article for an XAF example for both Windows and the Web platforms.
2. Implement a fully custom List Editor based on a treelist control configured as you need and then use it for the required ListView.