DATESBETWEEN

 Dates on the rows in a year. month, day hierarchy. Calculate YTD Sales.

Sales YTD =

VAR LastVisibleDate = MAX( 'Date'[Date] )

VAR CustomYTD =     DATESBETWEEN (

        'Date'[Date],

        DATE( YEAR ( LastVisibleDate ),  1,  1 ),

        LastVisibleDate

    )

RETURN

CALCULATE(

    [Sales Amount],

    CustomYTD 

)