Difference between Column values in a Matrix

[BItoken]

Hi,

I have a simple table with a date where the user will be able to select 2 dates and see the difference in Sum of Sales value between the selected dates as shown in the screen shot below.

User will be forced to select only 2 dates .

How do we achieve the difference instead of the sum of the selected 2 dates.

Attached is the link to the sample PBIX 

https://www.dropbox.com/s/cy2buewqw5bkj9c/test.pbix?dl=0

[Jihwan_Kim]

Diff measure : =
VAR _mindate =
CALCULATE ( MIN ( pbitest[rep_date] ), REMOVEFILTERS ( pbitest ) )
VAR _maxdate =
CALCULATE ( MAX ( pbitest[rep_date] ), REMOVEFILTERS ( pbitest ) )
VAR _diff =
CALCULATE ( SUM ( pbitest[atr] ), pbitest[rep_date] = _mindate )
- CALCULATE ( SUM ( pbitest[atr] ), pbitest[rep_date] = _maxdate )
RETURN
IF ( HASONEVALUE ( pbitest[rep_date] ), SUM ( pbitest[atr] ), _diff )

Link to the sample pbix file 

[BItoken]

@Jihwan_Kim Thanks for the response.

I tried creating this measure and row level differences are correct but i still see issue at the grand total of the Total (Difference).

The total difference for the 2 selected dates must be 701 as per the below screenshot

(250-149+600) but the total shows -329 (Looks like this -329 is consistent no matter what dates we select)

[Jihwan_Kim · Accepted solution]

https://www.dropbox.com/s/tct0pkypz9c7dgr/Test.pbix?dl=0 

[BItoken]

Thank u @Jihwan_Kim  it works now