Flexible Sections is a new plugin for Moodle course formats that allows you to nest or add hierarchy to your Moodle course’s topics. The plugin is contributed by Marina Glancy is and available only for Moodle 2.4. Topics can be collapsed or expanded and could be used to provide a more streamlined and succinct main course page.
Check out the plugin at https://moodle.org/plugins/view.php?plugin=format_flexsections.
For more course formats visit http://lmspulse.com/collections/course-formats/
This is cool! Some course structures demands subsections. Although I am wondering how does it work with other course sections? Like collapsible sections.