Summarizing a table to align most recent dates

Anonymous ,

Sorry, I misunderstood your needs before. You can try below measure.

(I can't very well restore your real date due to date formatting issues, so the results may change, but the logic should be correct.)

Measure:

Primary Source = 
IF(HASONEFILTER('Fact'[Branch]),
    CALCULATE(
        VAR tempTable = SUMMARIZE('Fact','Fact'[source ],"Recent3MonthsTotal",SUM('Fact'[qty]))
        VAR MaxNbr = MAXX(tempTable,[Recent3MonthsTotal])
        RETURN
        MAXX(FILTER(tempTable,[Recent3MonthsTotal]=MaxNbr),'Fact'[source ]),
        TOPN(3,VALUES('Fact'[month]),'Fact'[month])
    )
)

Table Expression:

Table Name = 
ADDCOLUMNS (
    ALL ( 'Fact'[Branch] ),
    "Parimay Source",
        CALCULATE(
            CALCULATE(
                VAR tempTable = SUMMARIZE('Fact','Fact'[source ],"Recent3MonthsTotal",SUM('Fact'[qty]))
                VAR MaxNbr = MAXX(tempTable,[Recent3MonthsTotal])
                RETURN
                MAXX(FILTER(tempTable,[Recent3MonthsTotal]=MaxNbr),'Fact'[source ]),
                TOPN(3,VALUES('Fact'[month]),'Fact'[month])
            )
        )
)