If you have been invited to more than one Account you can access them from the drop down menu under the FileSociety logo in the upper left.
Above the tool icon bar is a Navigation Bar to move between Library views.
The Back Arrow and Forward Arrow change to the previous and next library views. The Home icon changes the Library view to the User's top level Library. The Breadcrumbs navigation displays the path of the currently selected file or folder. Clicking on the name of a file/folder will make it the top level in the Library view.