Dax Measure to output "NA" when user selects more than one value on a Slicer

[Anonymous]

In my Power BI model, I have a scorecard on a Report and it is derived from a simple Measure:

Active Employees = CALCULATE(COUNTA(EmployeeTBL[empcode]),
                                 FILTER(EmployeeTBL,EmployeeTBL[Description] = "Active"))

The end user can interact with the value on that scorecard via a Month-Year Slicer (Jul 2019, Aug 2019,..). The values in that Slicer comes from the MthYrTxt column of the table "Date" (that is, Date[MthYrTxt]).

Here is what I want to achieve: if the user selects more than one value on that Slicer, I want the output on that scorecard to show "NA".

How can I achieve this?

[az38 · Accepted solution]

Hi @Anonymous 

it is unclear about relationships in your data model but try a measure

Active Employees = 

var _result = CALCULATE(COUNTA(EmployeeTBL[empcode]),
                                 FILTER(EmployeeTBL,EmployeeTBL[Description] = "Active"))
RETURN
IF (ISFILTERED(Date[MthYrTxt]) && calculate(count(Date[MthYrTxt])) > 1, "NA", _result)