Not really. array is a (misnamed) pointer to a pointer. It is not a 2D array. However, in some circumstances (eg the code example you gave, although I won't quote that again) a pointer to pointer can be treated as if it is a 2D array.
For Each ctrl As Control In Me.Controls("pnlMainPanel").Controls
If ctrl.GetType Is GetType(System.Windows.Forms.Panel) Then
For Each subCtrl As Control In ctrl.Controls
If subCtrl.GetType Is GetType(System.Windows.Forms.TextBox) Then
If subCtrl.GetType Is ...