Assign different venue to different time

Hi,

How can I assign different venue to different time of the same service?
I am expecting to have something like the picture attached.
3:00 <- Classroom A
3:20 <- Classroom B
3:40 <- Classroom C

Same service. Same employee.

I do not need to display the venue but I will need to attach the tag in the email. What tags should I use for venue and category?

Thanks.