Guys,

We've added groupby expand feature on Odoo Apps.

https://www.odoo.com/apps/modules/8.0/web_groupby_expand/

The web_menu module exists too from SerpentCS.

Hope this helps.

Thanks.

As i know, there is no a module that helps you expand or collapse the sidebar-menus in openerp 7.

But, you can change it by your self in the directory:

 v7/server/openerp/addons/base

Good Luck ;)