It seems that both controls are not very suitable out of the box, but with certain modifications you can achieve the desired result. Basically, you can display arbitrary hierarchy level by setting RowDetailsTemplate on each of the nested RadGridViews. Overriding the default sorting behavior of RadTreeListView to sort only the root level items would be more complex task and it may interfere with other core features of RadTreeListView, so I would still recommend RadGridView.
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