Shape.Parent Property (Visio)
Determines the parent of a Shape object. Read/write.
In general, an object's parent is the object that contains it. If a Shape object is a member of a group, the parent is that group. Otherwise, its parent is a Page or a Master object.
When assigning a new parent shape, you must assign a Shape object. If you want to assign a page or master to be the parent of a shape, you must assign the Shape object returned by the Page or Master object's PageSheet property.
A shape and its parent shape must be in the same containing page or containing master. If the new parent is not a Shape object, or if the ContainingPage or ContainingMaster property of the parent shape is different from that of the shape, Microsoft Visio raises an exception.