You can quickly filter the System Tree Items table so that it displays only assemblies.

Repeating this selection switches between hiding and showing parts in this table. When a checkmark appears beside this command, only assemblies are shown, even if branches are expanded. When no checkmark appears, both assemblies and parts are shown.

Selecting this command is equivalent to applying a filter with a selection criterion of Part = False. In either case, the hierarchal tree structure is retained.

If you apply any other filter to the System Tree Items table, this results in a flat list, which means that the table has no hierarchical levels. When any filter is applied to the System Tree Items table, you cannot insert, cut, copy, paste, move, or delete records. You also cannot change an assembly to a part. For more information, see Changing an Assembly to a Part.