Shell does not implement task pane

It seems to me that the current implementation of the shell does not include expandable controls. You can see an example of these types of controls when you activate the actions in the folder options: each group include a window that can be made visible or not by pressing a button on the top right of each item, by scrolling near groups for getting the required space.
At the moment I have no idea which interface implements this control and I have not found documentation even for using it in your own applications.
I have not found this stuff in the list of the missing feature of the shell in CORE-9277, so I posted it here.