How can I create stop more than one service being booked at the same time?

With my business, I offer many services, any of which can be offered at any time, but only one at a time. If I create multiple services in Appointments+, then people are able to book more than one of those services at the same time. How can I make it so that only one service can be booked at any given time? I can't figure out if this is possible using the "Capacity" setting.