you need to do "picking".
when you have multiple of the same object you need to filter it down to the exact one you want.
The question is how do you figure out which one you want. You can easily do System> Pick nearest/furthest and that should do it. But I don't know your game design so it's hard for me to say.
what I usually do if I have a static number of the same object - all in the layout before runtime - I assign the object an instance variable called "which". And then I assign each object a 'which' value. Like for buttons I might assign "info", "exit" and "start" as which values. Then when the mouse clicks on MenuButton (I have 3 of them in my layout) I make a sub-event that says
IF MenuButton.which = "info" THEN xyz...
IF MenuButton.which = "start" THEN xyz...
IF MenuButton.which = "exit" THEN xyz...
but that all depends if you create your objects through events.