You should query and bind the items as already shown in other threads opened by you:
You should adjusts the bound model fields to suit the control you would like to use. You can check and use similar properties as the Telerik.Web.UI.Widgets.DirectoryItem, as in the RadControls demos. Regarding the library filtering, this question is also asked in the above thread, which we and the community will help you resolve.
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and vote to affect the priority of the items