Ignore grouping if value is found

vahi, joepath 

I have a test on your sample pbix file, and find that why the msdnmeasure value shows 4 not 3.

Filter the data manually by conditional.

From the screenshot, you could find that "ORG_ENCOUNTER_KEY"=10013729, it has two rows data and it has different "USER_KEY", so in the calculation, it will be count by 2 not 1.

If you want that when you select  Newtype "msdnmeasure" value then column chart msdnmeasure value should show 3 not 4.

Please check that if you need to keep this conditional in your measure, if not, just remove the red part of the formula.

msdnNewMeasure = 
var _table= SUMMARIZE('Review Metrics'
,'Review Metrics'[ORG_ENCOUNTER_KEY],'Review Metrics'[Activity Date],'Review Metrics'[USER_KEY]
,"Review"
,IF(CALCULATE(COUNTA('Review Metrics'[Review Type]))= CALCULATE(COUNTA('Review Metrics'[Review Type]),
    FILTER('Review Metrics','Review Metrics'[Review Type]="Additional Review")),1,2))
return
COUNTROWS(FILTER(_table,[Review]=1))

Best Regards,

Lin