I've posted this in the Projects Site as well as the Documents Site
Some projects are very in depth and have multiple document layers. Once our users get 5/6 levels down, there isn't a great way to go back a step or two without hitting the back button. The breadcrumb option that they have is either for the Project as a whole or even the portfolio its listed under.
This creates additional work for our project managers, as they're having to navigate through the project longer than necessary.