The LearnDash Group Expiration module is used to expire course access for an entire group as well provide notification via email in advance of the expiration date. The notification can be customized and is always sent 7 days prior to group expiry to all group members.
This is useful when a number of organizations are set up with their own LearnDash Groups and you sell access to courses for a large group over a defined period of time. We see it used most often when organizations pay outside of WordPress for a bulk license to courses.
Visit the LearnDash Group Expiration knowledge base article for full details.