Motion tweening with actionscript

I’m trying to create a set of 4 vertically arranged buttons that ‘split’ apart when those buttons are pressed. For example, if you click the topmost (1st) button, the bottom three buttons will drop down so submenus (for the 1st button) can now be revealed beneath. Again, when you click the 2nd button from the top, the bottom two buttons drop down, revealing submenus, and so on.

Now, is there a way that I can use actionscripting to tween the buttons to not only motion tween a drop down when a button is first pressed, but also to motion tween the button to return up to its original spot when another button is then pressed? Right now, I have two keyframes, side-by-side which each containing a different y-scale value for an object. Can I do some actionscripting to get the object to motion tween upward to its original spot instead of “clicking,” or snapping back to is original spot when another button is pressed?

If this is hard to understand, let me know and I’ll word this differently. Thanks!