you can "force" Listbox3 to filter (based on Listbox2), by adding additional code
ot Listbox1 AfterUpdate event.
Private Sub Listbox1_BeforeUpdate(Cancel As Integer)
Listbox2.Requery
If Listbox2.ListCount <> 0 Then
Listbox2 = Listbox2.ItemData(0)
End If
Listbox3.Requery
End Sub