Final client status by grouping on selected date range

Hello all,

I have found solution to my problem. Here is the code:

CountOfMaxStatus = COUNTROWS(
FILTER (
        TestData;
        TestData[TimeStamp]
            = CALCULATE (
                MAX ( TestData[TimeStamp] );
                FILTER(ALL(TestData);TestData[Client] = EARLIER ( TestData[Client]));
                FILTER(ALL(TestData);TestData[TimeStamp]>=MIN(DateTimeDimension[TimeStamp]));
                filter(ALL(TestData);TestData[TimeStamp]<=MAX(DateTimeDimension[TimeStamp]))
            )
))

Here is link to the pbix file if you want to see it in the action: http://www.filedropper.com/maxstatusmeasure

Thanks AlB and v-lili6-msft for the help.