This is most often referred to as a "disclosure view" or "disclosure panel" and usually has to come with an intelligent container view (that grows/shrinks/scrolls correctly with multiple disclosure subviews). There is no such control as part of the API. Most developers roll their own while some use third-party open source.
The Omni Frameworks have one such control that works very well (including "tear-off" panels, etc., if I recall correctly). The drawback: it's a large framework and has a lot of other stuff in it as well.
InspectorKit is another. It's more focused (just the control itself and an IB plugin), but the last incarnation I tested did have a few UI issues with the Interface Builder plugin.