Nested Repeating Groups? Grouping?

Hello Team, I am really struggling trying to get my head around nested repeating groups and grouping within them. It’s entirely possible I am not using the correct solution.

The scenario is a system for booking jobs for resources. I have the booking side working fine with a datatype of “jobs” which holds all the booking details, time/date, resource used, who is using it. It is possible for more than one booking to be made for a resource at the same time.

My issue is in displaying the bookings grouped in a meaningful way. Something like this:

Date/Time #1
Resource #1
Booking #1
Booking #2
Booking #3
Resource #2
Booking #1
Booking #2
Booking #3

Date/Time #2
Resource #1
Booking #1
Booking #2
Booking #3
Resource #2
Booking #1
Booking #2
Booking #3

I want to do this in a WU economical way so I have loaded all the booking data into a custom state on page load and I’d like to work with that data.

I have been able to group the bookings together by date (by using repeating group, group by) but cannot find a way to group them at the next level by resource.

Cheers