Need a measure to return minimum dates for each rows

Hi,

I am not sure if I understood your question correctly, but I assumed the expected outcome shows minimum date for the groups of minus stocks or plus stocks.

Please check the below picture and the attached pbix file.

All measures are in the attached pbix file, and each of them are numbered as a step to follow.

step one plus minus change index: = 
VAR _currentstock =
    SUM ( Data[stock] )
VAR _currentdate =
    MAX ( Data[date] )
VAR _currentmaterial =
    MAX ( Data[material] )
VAR _previousdate =
    MAXX (
        FILTER (
            ALL ( Data ),
            Data[material] = _currentmaterial
                && Data[date] < _currentdate
        ),
        Data[date]
    )
VAR _previousstock =
    SUMX (
        FILTER (
            ALL ( Data ),
            Data[material] = _currentmaterial
                && Data[date] = _previousdate
        ),
        Data[stock]
    )
RETURN
IF( HASONEVALUE( Data[date]),
    IF ( _currentstock * _previousstock < 0, 1, 0 )
)

step two Group of change index: = 
IF (
    HASONEVALUE ( Data[date] ),
    SUMX (
        FILTER (
            ALL ( Data ),
            Data[material] = MAX ( Data[material] )
                && Data[date] <= MAX ( Data[date] )
        ),
        [step one plus minus change index:]
    )
)

step three group by step two: = 
VAR _currentgroup = [step two Group of change index:]
VAR _newtable =
    FILTER (
        ADDCOLUMNS (
            FILTER ( ALL ( Data ), Data[material] = MAX ( Data[material] ) ),
            "@group", [step two Group of change index:],
            "@stock", CALCULATE ( SUM ( Data[stock] ) )
        ),
        [@group] = _currentgroup
    )
VAR _findminstock =
    MAXX (
        GROUPBY ( _newtable, [@group], "@minstock", MINX ( CURRENTGROUP (), [@stock] ) ),
        [@minstock]
    )
RETURN
    IF (
        HASONEVALUE ( Data[date] ),
        MAXX ( FILTER ( _newtable, Data[stock] = _findminstock ), Data[date] )
    )

thanks again Jihwan_Kim  have a good day 🙂