When using LoadOnDemand in a RadTreeList, it would be great to have it automatically expand to a selected item when initially loading on a page.
The TreeList can not know which items to expand to reach the selected one. So the only possible solution will be some custom code. Using backtracking in your database. Since you know the relations in your database, use the selected item, find it's parent and so on until you get to the root. Store the items that should be expanded. Later on, expand the items in the TreeList based on your data.