Right-clicking the background of the Hierarchy Views opens a pop-up menu, which allows you to define and use several display and background properties:
Increase zoom. Enlarges the size of the view elements. Pressing the shortcut key "+" has a similar effect.
Decrease zoom. Reduces the size of the view elements. Pressing the shortcut key "-" has a similar effect.
Center. Jumps at the center of the view. Pressing the shortcut key Ctrl+A has a similar effect.
Select All. Selects all visible objects of the view.
Set Background Picture.... Opens the Background Picture Properties view for setting a background picture.
Arrange Automatically. Toggles automatic arranging of elements on or off.
Add Shape : This submenu contains all shape types defined for the model and allows you to add a shape easily to the Hierarchy Views.