You can right click on the tree view or the file list and a context menu will pop up, offering several choices of action.
The tree view context menu allows you to select a group of items, hide or reveal a group of items, open a group of items; or configure your favorite zip folders. Some selections will be available only when a certain item is selected in the tree view.
The file list context menu allows you to customize the way the icons appear in the file list, and the way they are sorted.