Public Sub CheckBox1_Click()
  ShowHideLayer "To Be Form", CheckBox1.Value
End Sub

Public Sub CheckBox2_Click()
  ShowHideLayer "SHC As Is Form", CheckBox2.Value
End Sub

Public Sub CheckBox3_Click()
  ShowHideLayer "Works As Is Form", CheckBox3.Value
End Sub

Public Sub ShowHideLayer(sLayerName As String, bShow As Boolean)
  Dim aPage As Visio.Page, aLayer As Visio.Layer, aCell As Visio.Cell
  
  For Each aPage In ActiveDocument.Pages
    For Each aLayer In aPage.Layers
      If aLayer.Name = sLayerName Then
        Set aCell = aLayer.CellsC(visLayerVisible)
        aCell.Formula = bShow
      End If
    Next aLayer
  Next aPage
End Sub