Custom Navigation Based On Page Attributes

I'm building a site which will work as a hall of fame. Administrators will add people to the site based on the year they graduated from a university. The site will also have two pages for graduates who were a part of the Olympic and Commonwealth games - the pages will be the same but some should be accessible from the separate menu.

How would I / which functions should I be using to create navigation for this? In my mind I would be able to add a checkbox attribute / tag / category to the pages which the admin's will be able to check and the pages will be included in the navigation.