This module provides an efficient and flexible way of storing content in a hierarchy. You can use this hierarchy for site menus, scoped searches, and node references.
- Hierarchy field: use CCK fields to create and maintain node trees for your site
- Hierarchy menu: Show your hierarchies in the primary and secondary links menu, or from within a correctly-nested block.
- Hierarchy: A generalized hierarchy API, which stores the hierarchical links and provides views integration
This module is still in devleopment, and your mileage may vary.