That worked perfectly... and much easier to add additional controls with your code version.
I added the checkboxes from Developer tab....Insert...Check Box (ActiveX Control).


For any other non-VBA coder who might happen to come across this post because of they have the same need as me:

added page 1 in front of my document;
assigned only one layer to the objects (must be only one layer assigned) which I wanted to hide/show throughout the document;
added the checkboxes, as just described above, into page 1;
pasted the macro into the macro enabled file;
ensured the checkbox number given by Visio and the assigned layer name corresponds to the appropriate macro section.


Now with a simple check or uncheck that layer becomes visible or hidden in all the pages throughout the entire document.


Thanks very much!