Multiple service offerings, how to make sure only one time slot can book only one service

Hi,
I have created several service options in the Appointment options. All of the fall under the same day/time slot; I did a test by booking one service at 10am, and hoping the rest won't show up. However, other services are still showing up.

How do i make it, so that after One service is booked for a certain time, the other services will not be able to book under the same time slot?

thanks.