You can read full documentation for the modern WordPress version over here: Foliopress Embedded Page Menus.
The original Mambo version was much more limited than the current WordPress version which basically feeds and washes and walks your dog for you, giving you menus in every nick and cranny of your website with more or less information.
But Mambo didn't need any help structuring a CMS. Mambo Embedded Page Menus were the backbone of the Calum Ross mortgage consulting site, a site which was more or less unchanged from 2004 to 2007, at the core of the Calum Ross Mortage Consulting team, doing millions of dollars of commissions per year.
This plugin was tested with Mambo 4.5.1 and probably needs updating to work with current Mambo or Joomla. On the other hand, the plugin is very simple and leverages core Mambo functionality so it shouldn't be much trouble to update.
Installation is just like any Mambo module:
[drain file 3 url]
Mambo Embedded Page Menus is a free download, no registration required.
But if you find Mambo Embedded Page Menus useful, please drop by and leave a link to a page of your site with Mambo Embedded Page Menus in action in the comments. Anchor text encouraged!