These buttons are able to display a popup menu with most recent history (Back and Forward buttons) or some upper level paths (Up button). To show this menu click them with right mouse button, or press left mouse button and hold it pressed for half a second. Then you can select a new path from the popup menu.
Popup menus
Some toolbar buttons have display a popup menu with button related commands when clicked with right or middle mouse button.
Notes
There may be only one LocationEntry and FilterEntry item displayed. If two or more toolbars have these items only the first one will be displayed, but it is not treated as error condition. Also text entries can't be displayed on vertical toolbars.
When you change filtering pattern in FilterEntry you must press enter while cursor is in this entry to activate the filter even if you choose pattern from the combo list. Hopefully this will be fixed later.
LocationEntry is not yet editable. Later it will allow you to edit paths directly.