I am new to Eggplant so I am trying to find a way to find and/or select a button that is hidden by a drop down menu.
When you begin using eggPlant it is good to think about it as a user sitting in front of the system under test (SUT). It uses the interface just the way a user does, so it cannot perform actions that a user would not be able to perform (although sometimes it can complete them more quickly than a human user could).
If a user sitting in front of the computer would not be able to click or select the button in question while the menu was open, then the menu will need to be closed before the button can be selected.
I would recommend using an image to have eggPlant perform the action of closing the menu the same way a user would. Whatever must be clicked to close the menu, capture an image of that and have eggPlant click it.
I hope that helps!