PreviousCOODate = 
VAR CurrentCOODate =
    SELECTEDVALUE('DIM - Date Table'[Date])

RETURN

CALCULATE (
    MAX ( 'DIM - Date Table'[Date] ),
    ALL ( ),
    'DIM - Date Table'[Date] < CurrentCOODate,
    'DIM - Date Table'[IsWorkingDay] = 1
)