The Collapsable Sidebar allows you to hide/show menu items that are nested underneath a heading. This can be helpful for long sidebar menus where items fall into clear categories within a section.
How to use
The collapsable sidebar is a menu module. To use it, you must select "sidebar-collapsable" as the layout under the advanced tab. The collapsable sidebar must be placed in the sidebar position. It cannot be used in any other position.
The collapsable sidebar is designed to be used on menus that are up to a maximium of three levels down. The first level can either be a link or a heading. It's not possible for the first level to be collapsable. Only the second level items with sub items can be collapsable. Second level items must be menu headings with sub items in order to be collapsable.