Dragging Components to Edit the Assembly Structure
To reorganize components in sub-assemblies by dragging components:
Drag the component icon in the FeatureManager design tree, and drop it on the icon for the destination assembly (either the top-level assembly, or a sub-assembly at any level of the hierarchy).
If the destination assembly is expanded, you can also drop the icon in the component section of the destination assembly. As you drag, watch for the pointer.
To move multiple components at once, hold Ctrl as you select the icons. All the components selected for a move operation must be from the same level of a single assembly.
If any components or features will be deleted as a result of the move, the Assembly Structure Editing dialog box appears, with a list of the affected items.
If you are removing the last component of a sub-assembly, the empty sub-assembly is left in the FeatureManager design tree. If you want to move the last component up a level and remove the empty sub-assembly at the same time,
dissolve the sub-assembly
You can also drag components to change their order within an assembly.