Folders Pane contains a tree view of directories. Clicking on a folder in the tree view starts reloading photographs from this folder. Right clicking on the folder brings up a context menu with a tree view refresh option and subfolder scanning option.
Currently selected folder can be added to the favorite folders list (Favorites/Add to Favorites).
Each folder beeing scanned is remembered in a list of recently used paths. First toolbar button reveals this list, while the second button goes to the parent folder.