Looking for a plugin that will provide page level (section

Looking for a plugin that will provide page level (section level, actually) control over what pages get displayed in the sidebar navigation menu. The Home page of our site functions as a kind of entry point into three fairly distinct sections. Each section will have its own set of links. So for, example, imagine the front page has these three image links:

front office
back office
customer support

User clicks "front office" and sees a landing page for the "front office" section of the site. Clicks any of the links on that (sub)landing page and the sidebar should just show front office links in the sidebar menu.

Any ideas? Thanks in advance...