What exactly are you trying to accomplish? Do you want to trigger an event when a player clicks an object that is overlapping the background? Do want to trigger the event only when the player clicks where the 2 objects are overlapping (in other words inside the area of overlap)? Do you want to trigger the event when a player clicks where no objects are overlapping? What do you mean by "check for invert overlapping?"
I tried to decipher what it is you need help with, but could not completely understand. That being said, I am attaching a .capx file that has an example of how to check if an object is clicked, if the clicked object overlaps another object at the click location or if no objects were clicked.
I hope it helps and good luck with your project.