The Path Field shows the current path displayed in the active Explorer Panel . Sub folders in the path that is shown are clickable. Clicking on a subpath causes the Explorer Panel to try to change to that path.
If you hold down the CTRL key while clicking on a sub folder a list of all the sub-folders under that path will be shown. You can then select a sub-folder that you want to go to from that list.
Editing the Path Field
By double clicking on the empty space in the path field, it will become an editable path. If the path is changed the Explorer Panel will try to change to the new path.