Preparing for an Assessment Center: Where Can I Find Business Cases to Practice?

I am about to enter an assessment center. It will include a Business Case, Discussion Group, and One-to-One sessions. I am looking for Business cases to prepare for participation. Please share or advise me on where to buy them. On the other hand, anything related to this context will add value.

I am moving from Sr. Supervisor to Manager, and I have to work on a business case. So, I need to participate.