DAX Help

Hi,

For what i understood you need the difference from last day of the month and first day of the month, for each month, for the column [Actual Spending].

So, i created two colums, Month_Year, and Amplitude, it goes like this

Month_Year = MONTH(Plan1[Calendar Date]) & "/" & YEAR(Plan1[Calendar Date])

Amplitude = 
VAR SPENDING_LAST_DAY = CALCULATE(
    SUM(Plan1[Actual Spending]),
    FILTER(
    ALL(Plan1),
        EARLIER(Plan1[Center-Account]) = Plan1[Center-Account] && EARLIER(Plan1[Month_Year]) = Plan1[Month_Year] && ENDOFMONTH(Plan1[Calendar Date]) = Plan1[Calendar Date]
    )
)

VAR SPENDING_FIRST_DAY = CALCULATE(
    SUM(Plan1[Actual Spending]),
    FILTER(
    ALL(Plan1),
        EARLIER(Plan1[Center-Account]) = Plan1[Center-Account] && EARLIER(Plan1[Month_Year]) = Plan1[Month_Year] && STARTOFMONTH(Plan1[Calendar Date]) = Plan1[Calendar Date]
    )
)

RETURN SPENDING_LAST_DAY-SPENDING_FIRST_DAY

The result 

with this column you can do all of the other things like a top 20, and a calendar filter would work in any interval you want.

Theres probably a cleaner way to do it but, i hope that helps.