Harvard Business Review Case Studies, in most cases, are only available through individual purchase. They are extremely strict about lending through libraries or colleges, or having libraries/business schools purchase them on behalf of students.
We do have access to the HBR online for everything EXCEPT most of the cases – all the other content (articles, book reviews, essays, editorials) here.
I’m afraid that in most cases the only way to get a recent HBR case study is to purchase it.