I'd like a menu structure that is something like the following to be placed into a page's sidebar.
I'd like it to be set up so that if a user is on the bears page, the animals and mammals menus will be expanded...but the user COULD click an arrow next to reptiles to have that menu expand, and see the snakes option. When I checked the $page['sidebar'] render array, however, child menu items that are not expanded are not even included in the array. So, if I am on bears, there is nothing below $page['sidebar'][whatever number reptiles is]
I thought about writing a module that builds this through the DB, but at that point I'd be pretty much re-writing and implementing the menu modulem since I'd need to also include the html output of this new data on the page. What's the best way to approach this?