If you comment on an article there's apparently no way to find any replies to it. Even on this Forums page, there's a huge 'Threads with your posts' item at the top, but that takes you to a just a ...
The video gives an overview of how discussions forums can be used in online teaching and with groups. Note: this video is based on Moodle 3.5 though much of the explanations relate to the updated 3.9.