Simple count of unique responses by location

So I did achieve the results I desired in this case but not sure if this is the most efficient design pattern.

In my Data Flow, I created a new table

Select
`LocationID`,
`Location`,
COUNT(DISTINCT `ResponseGroupID`) as 'Distinct ResponseGroupID'
From `ajh_rounding_recursive_final_output`
Group BY `LocationID`

Then joined this new table to the main output (shown in the second LEFT JOIN below)

SELECT 
rm.`Measure` AS "RoundingMeasures.Measure",
rm.`Section` AS "RoundingMeasures.Section",
rm.`ID` AS "RoundingMeasures.ID",
rd.`MeasureID` ,

rd.`ID`  ,
rd.`ResponseGroupID` ,

rd.`Comments` ,
rd.`Created` ,
rd.`Date` ,
rd.`SubmittedBy`,
rd.`Location` ,
rd.`LocationID` ,

rgi.`Distinct ResponseGroupID`

FROM
`tbl_rounding_data` rd 
LEFT JOIN
`ajh_rounding_measures` rm
ON rd.`MeasureID` = rm.`ID`
LEFT JOIN
`tbl_responsegroupids_by_location` rgi
ON rd.`LocationID` = rgi.`LocationID`

Then, in a data card, I can use "MAX" as an aggregation (each value is the same for every entry of the location) and it gives me what is shown below.

Table 

My question is, is this this the best way to do this? If I wanted to count how many distinct ResponseGroupIDs there were by person, do I have to build this out as a separate table too (I don't mind, just want to make sure I'm not missing a much easier way to approach this)?

Thanks for reading and for your recommendations!