Showing the Book Explorer
Use this tool to open the ToolBook Book Explorer. This is the equivalent of the ToolBook menu combination View -> Book Explorer or Shift+F4.
The ToolBook Book Explorer allows you to view pages/backgrounds and see their objects. You can move pages or objects, right-click to get to their properties, show or hide objects, and much more. It is normally only displayed at author level, but you can use this button to display the Book Explorer at reader level as well.