> one is "take me one level up the hierarchy." They're often but not always the same.

Who expects this behavior? It doesn't make sense. You just want to go back where you were. Most file browsers I've used wanting to implement going up a level in hierarchy, have an arrow pointing up.

GNU Info and many Web 1.0 navigation schemes involved a hierarchy which did involve "Next", "Previous", "Up", and "Home" type dimensions.

For example, the Bacula documentation is still online, as a prime example of this: https://www.bacula.org/9.6.x-manuals/en/main/Getting_Started...

Nobody