In the left and right panes, there are several ways to navigate through the folders list.
You can open a container by double-clicking it. This expands the container so that the left pane shows its containers, and the right pane shows its contents.
Alternatively, click the Collapse/Expand button to the left of the container.
To close an open container, double-click it (or click its Collapse/Expand button in the left pane).
You can also move up in the folders list by choosing objects in the Context dropdown list.
You can also use the arrow keys to navigate through the folders list.