You can Follow the original request for that component here: https://feedback.telerik.com/blazor/1456580-dropdowntree. I am marking this one as a duplicate to keep the portal tidy and avoid confusion. I've also added your Vote to it to raise its priority (you can also vote on your own by clicking the Vote button on items that interest you), and you can find a workaround posted in that thread that you can use for the time being.
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