If you would like to know what activities a specific client has booked, there are two ways for you to do it.
OPTION 1
1. Click on Contacts and then look for the client profile.
2. Click on Bookings and you will be able to see the list of upcoming or past bookings.
OPTION 2
1. Click on Analytics > Reports
2. Choose Class Bookings (Or Appointments bookings if you want to check the appointment booking history)
3. You will have access to check the booking history or export it.