As far as I understood your scenario, you want to be able to only to select the directories in the TreeView, and perform all other operations in the Grid. This is not possible with the current implementation of the RadFileExplorer control. The operations (delete/rename/copy and etc.) do not know whether the selected items are in the tree or the grid. They only know whether a file (or folder) is selected or not. Nothing more.
Moreover, the treeview, grid and toolbar are tightly interdependent among each other and it is not possible to isolate the tree from the group and execute file operations only on the grid.
the Telerik team
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