Version:            (using KDE 4.3.2)
Installed from:    I Don't Know

This idea is an extension of the existing Dolphin breadcrumb address bar:

The first one is an improvement on the breadcrumb navigation bar:

See Attachment

In this, as you can see, the list of folders you get by clicking the arrows between each folder in the bar has been expanded into a full tree-style navigation system, allowing you to navigate up to any folder in the hierarchy. If there were subfolders in the mythtv folder, you would be able to navigate to those, and subfolders of those subfolders, etc. You can see that not every folder has an arrow. That is because the arrow only appears when there is a subfolder you can navigate to.