Per Unit Computation Dax

Hi icdns ,

I download you sample and have test. Firstly I suggest to to sort [Month] column by [MonthNo] column.

For reference: Sort one column by another column in Power BI Desktop

Then create a measure as below to achieve your goal.

Sales Percentage = 
VAR _SUMMARIZE =
    SUMMARIZE (
        ALLSELECTED ( sampledata ),
        sampledata[Year],
        sampledata[Month],
        sampledata[City],
        "Sales", CALCULATE ( SUM ( sampledata[Sales] ) )
    )
VAR _ADDMAX =
    ADDCOLUMNS (
        _SUMMARIZE,
        "MaxSales", MAXX ( FILTER ( _SUMMARIZE, [City] = EARLIER ( [City] ) ), [Sales] )
    )
VAR _Sales =
    CALCULATE ( SUM ( sampledata[Sales] ) )
VAR _MaxSales =
    MAXX ( FILTER ( _ADDMAX, [City] = MAX ( sampledata[City] ) ), [MaxSales] )
RETURN
    DIVIDE ( _Sales, _MaxSales )

Result is as below.

Best Regards,
Rico Zhou

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