Is the gameobject is on the same level with it's surface on which it is located?

Hi everyone. I am pretty new to Unity and maybe my question would be not clear for you but I will try to explain. I have a coffeemachine virtual prototype in unity and there are 3 buttons on coffee machine. What I want to do is to find out if the buttons are on the same level with the surface(plane) on which these buttons are located or they raised above it. It will be great if someone will give me some direction on how can I do it.