Changing How a Computed BOM Hierarchy Displays

In the View (left) section of the BOM toolbar, expand the BOM View flyout BOM_UI_Indented and select one of the following:

BOM_UI_Indented Indented Parts and subassemblies are indented from their parent assemblies in this hierarchical view (default).
BOM_UI_Parts_Only Parts Only Only parts are listed in the BOM in a flat view. Quantities for parts referenced by more than one subassembly are accumulated.
BOM_UI_Top_Level_Only Top Level Only Only top level entries in the BOM list are displayed.