The Yii Framework provides a sweet functionality that allows you to easily create page specific menus.
What does this mean?
This allows you to create one layout or CSS styling for your menu, and when each page is loaded, a new set of menu items is loaded in. This is useful for context specific sidebars within your application.
I assume you are familiar with accessControl standard filter. It allows you to separate privileges to run some action from action code itself. There is however one problem with most common usage - you cannot use bizRules, at least based on some parameters passed to 'checkAccess' just because it is hard to pass them in accessRules() result.