Mix% (Dynamic date filters, NaturalInnerjoin, Summarize)

Hi Praful_Potphode ,

Please refer to the pbix below attatctched, and refer to the power query steps to get your desired output.

Hope this helps.
Thank you.

barkha 
Ok, I had the chance to implement the solution in the attached sample file.

QAQB = () => 
VAR base_rank =
    SELECTEDVALUE ( BaseCalendar[Rank] )
VAR actual_rank =
    SELECTEDVALUE ( ActualCalendar[Rank] )
VAR timePeriod =
    SELECTEDVALUE ( TimePeriod[SelectedPeriod] ) - 1 
// 1.
VAR tbl1 =
    SUMMARIZE (
        FILTER (
            CleanSales,
            CleanSales[rank] >= base_rank - timePeriod && CleanSales[rank] <= base_rank
        ),
        All_CustomerIDs[CustomerNo],
        All_SKUCode[SKUCode],
        "QuantityB", SUM ( CleanSales[Quantity] )
    ) 
// 2.
VAR tbl2 =
    SUMMARIZE (
        FILTER (
            CleanSales,
            CleanSales[rank] >= actual_rank - timePeriod && CleanSales[rank] <= actual_rank
        ),
        All_CustomerIDs[CustomerNo],
        All_SKUCode[SKUCode],
        "QuantityA", SUM ( CleanSales[Quantity] )
    ) 
// 3.
VAR InnerJoinTable1 =
    NATURALINNERJOIN ( tbl1, tbl2 ) 
RETURN
    InnerJoinTable1

MAMB = () => 
VAR base_rank =
    SELECTEDVALUE ( BaseCalendar[Rank] )
VAR actual_rank =
    SELECTEDVALUE ( ActualCalendar[Rank] )
VAR timePeriod =
    SELECTEDVALUE ( TimePeriod[SelectedPeriod] ) - 1 
// 4.
VAR tbl3 =
    CALCULATETABLE (
        SUMMARIZE (
            FILTER (
                CleanSales,
                CleanSales[rank] >= base_rank - timePeriod && CleanSales[rank] <= base_rank
            ),
            All_CustomerIDs[CustomerNo],
            All_SKUCode[SKUCode],
            "QuantityB", SUM ( CleanSales[Quantity] )
        ),
        ALL ( All_SKUCode[SKUCode] )
    ) 
// 5.
VAR tbl4 =
    CALCULATETABLE (
        SUMMARIZE (
            FILTER (
                CleanSales,
                CleanSales[rank] >= actual_rank - timePeriod && CleanSales[rank] <= actual_rank
            ),
            All_CustomerIDs[CustomerNo],
            All_SKUCode[SKUCode],
            "QuantityA", SUM ( CleanSales[Quantity] )
        ),
        ALL ( All_SKUCode[SKUCode] )
    ) 
// 6.
VAR InnerJoinTable2 =
    NATURALINNERJOIN ( tbl3, tbl4 ) 
// 7.
VAR CustomerTotals =
    GROUPBY (
        InnerJoinTable2,
        All_CustomerIDs[CustomerNo],
        "TotalBaseQuantity", SUMX ( CURRENTGROUP (), [QuantityB] ),
        "TotalActualQuantity", SUMX ( CURRENTGROUP (), [QuantityA] )
    ) 
// 8. Merge totals back
VAR FullWithTotals =
    NATURALLEFTOUTERJOIN ( QAQB(), CustomerTotals ) 
// 9.
VAR MAMB =
    ADDCOLUMNS (
        FullWithTotals,
        "Mn_A", DIVIDE ( [QuantityA], [TotalActualQuantity], 0 ),
        "Mn_B", DIVIDE ( [QuantityB], [TotalBaseQuantity], 0 )
    )
RETURN
    MAMB

CY Quantity = SUMX ( QAQB(), [QuantityB])

CY Mix = AVERAGEX ( MAMB(), [Mn_B] )

PY Quantity = SUMX ( QAQB(), [QuantityA] )

PY Mix = AVERAGEX ( MAMB(), [Mn_A] )