Sweet Button - Launching Expose
Here is a short tutorial on how to launch an Expose Stack lightbox form a Sweet Button stack.
Take note of the Expose class in Edit Mode.
You can leave the Expose Launcher empty if you only want to launch the lightbox only via the sweet button. You probably want to add some content to the Expose lightbox though.
Add a class attribute into Sweet Button
When you click on the link button in Sweet Button, you will need to create a new attribute for class. Set the value to the class that is defined in the Expose stack in bold.