Sorting with multiple fields in DPA?

Trying to find some info about sorting with multiple fields in DPA?

Basic scenario is that I'm trying to use the DPA reporting to sort Avamar clients by both Domain Name and Client Name, so that I get a listing with both values relative to the following:

Domains named A, B, C

Domain A clients named sys31, sys32, sys33

Domain B clients named sys24, sys25, sys26

Domain C clients named sys17, sys18, sys19

The output needs to be sorted and reported so it shows up as:

A   sys31

A   sys32

A   sys33

B   sys24

B   sys25

B   sys26

C   sys17

C   sys18

C   sys19

Do I have to "feed" the same data source into two separate Order operators and then Merge them into the Report? And if I wanted to "operate" on other data fields that aren't being sorted, should I be doing that before or after the merge?

(and for those interested, the end goal is to be able to have a Backup Client Schedule timeline report where the Avamar clients on the Y axis are listed in the above format of Domain followed by Client; also having trouble figuring out how to change the Y-axis labels in that chart - that's likely another discussion in itself)

All comments/feedback appreciated - thanks.