Moving a System Tree Item
You can move an assembly or part in the System Tree Items table to a new location using the standard Windows drag-and-drop technique.
To move an item as a sibling to another item, click and drag the item until it is over the item where you want to place it and then release the mouse button.
To move an item as a child to another item, click and drag the item while pressing and holding down Shift until it is over the item where you want to place it; then, release the mouse button and Shift.