The result should like this:

Note: This image is a LabVIEW snippet, which includes LabVIEW code that you can reuse in your project. To use a snippet, right-click the image, save it to your computer, and drag the file onto your LabVIEW diagram.
With this code, the button that gets pressed would give a different index value that then can be used to open a different menu with more groups of buttons or processes without using more event structures.