To prepare for an interview I have three suggestions:
Be ready to talk about previous work that points to you being able to manage clients, including their requests, project expectations, and budgets. It will be especially important to talk about how you are capable of delivering bad news as well as how you can optimize research to answer as many questions as possible for clients.
Expect a case study where you are given a data set and must tell a story that speaks to a business case and provide a recommendation for the client to use in their decision making.
You will work with analysts that support your team as a manager, so it will be vital that you can talk about managing people's workloads, while also helping them grow with regards to data analysis, business writing, and client interaction.