Change payment every month

Hi Anonymous 
Here is a sample file with the propsed solution https://www.dropbox.com/t/i3qSlzaPNNMgXE9D

Monthly Salary Column = 
VAR CurrentRate = employee[Payment per hour]
VAR CurrentMonth = MONTH (  employee[Date] )
VAR CurrentYear = YEAR ( employee[Date] )
RETURN
    SUMX (
        FILTER ( 
            RELATEDTABLE ( attendance ), 
            MONTH ( attendance[Date] ) = CurrentMonth
                && YEAR ( attendance[Date] ) = CurrentYear
        ),
        VAR Clockin = attendance[Clock in]
        VAR Clockout = attendance[Clock Out]
        VAR NumberOfHours = DATEDIFF ( Clockin, Clockout, HOUR )
        RETURN
            CurrentRate * NumberOfHours
    )

Monthly Salary Measure = 
SUMX (
    employee,
    VAR CurrentRate = employee[Payment per hour]
    VAR CurrentMonth = MONTH (  employee[Date] )
    VAR CurrentYear = YEAR ( employee[Date] )
    RETURN
        SUMX (
            FILTER ( 
                RELATEDTABLE ( attendance ), 
                MONTH ( attendance[Date] ) = CurrentMonth
                    && YEAR ( attendance[Date] ) = CurrentYear
            ),
            VAR Clockin = attendance[Clock in]
            VAR Clockout = attendance[Clock Out]
            VAR NumberOfHours = DATEDIFF ( Clockin, Clockout, HOUR )
            RETURN
                CurrentRate * NumberOfHours
        )
)