previous week calculation repeating over empty dates weekly to daily relationship

 datacode 
Ok, that was stupidly simple. The SELECTEDVALUE ( Lookup_Calendar[Date] ) has a value in each single date which forces the engine to display the values for all dates. This is supposed to be SELECTEDVALUE ( Data[Date] ). Please refer to attached sample file.

PREVIOUSWEEK Value WDT = 
VAR _Today =
    SELECTEDVALUE(Data[Date])
VAR _WOT =
    WEEKNUM( _Today, 1 ) -- Number 2 determines that the week begins on Monday.
VAR _LW = _WOT - 1
VAR Result =
    CALCULATE(
        SUM( Data[Units]),
        FILTER(
            ALLSELECTED( Lookup_Calendar ),
            Lookup_Calendar[Week Of Year] = _LW
                && Lookup_Calendar[Year] = YEAR(_Today )
        )
    )
RETURN
    Result