Visio 2010
File name: Octagonal Planter.vsd
Tab name: 13-Inch (a drawing of a cement mold). Can change name to simplify code.
Layer name: Construction. Command Button 1.
Layer name: Cement Fill. Command Button 2.

Cement Fill layer is over (in front of) Construction layer.

What would the code be to use a single button to toggle each layer on or off independently?

Would I put the code behind each button, or in a module? There are eight tabs with different drawings/names.