PreviousSubdocument Method
From Microsoft Word Visual Basic
Moves the range or selection to the previous subdocument. If there isn't another subdocument, an error occurs.
expression.PreviousSubdocument
expression Required. An expression that returns a Range or Selection object.
Example
This example switches the active document to master document view and selects the previous subdocument.
If ActiveDocument.Subdocuments.Count >= 1 Then
ActiveDocument.ActiveWindow.View.Type = wdMasterView
Selection.EndKey Unit:=wdStory, Extend:=wdMove
Selection.PreviousSubdocument
End If