Use CollectionViewSource to sort and group data in XAML. : CollectionViewSource « Windows Presentation Foundation « VB.Net Tutorial
GitHub - nosalan/wpf-mvvm-datagrid-with-filtering: An example of WPF Datagrid with Filtering capability and expandable headers. Coded in MVVM style.
GitHub - SyncfusionExamples/How-to-apply-filters-in-wpf-treeview-using- collectionview-type-sources: This example describes how to apply filters in wpf treeview using collectionview type sources.
![CollectionViewSource is crazy useful for binding to filtered Observable Collections on Windows Phone 8 - Scott Hanselman's Blog CollectionViewSource is crazy useful for binding to filtered Observable Collections on Windows Phone 8 - Scott Hanselman's Blog](https://hanselmanblogcontent.azureedge.net/Windows-Live-Writer/CollectionViewSource-is-crazy-useful-for_122F5/image_b5516dd4-31b0-422b-8742-9bc1fbfa5d12.png)