filter grid view by treeview

i want to filter grid view by treeview (e.g when i chose programming category show all books where category==programming or be a subset of programming (like c#, Java and...))

i bind treeview with book entity and i create a list of selected category and all Its subsidiaries
private void createNodeList(TreeNode treeNode) { List<int> catList = new List<int&g ...