Date slicer showing multiple months, update measures to only show the last months data.

[Natty_008]

Hello, wondering if someone can help me with a Date slicer / measure question. 

I have a sales table linked to DATE_DIM table.

The Date slicer is to select the period(multiple months) so I can get the YTD sales figures. However I would like to update some of my measures to only display the last month on the date slicer.

For an example is I am showing YTD sales for July - December period, how can I write the measure to calculate the sales based on the last month selected in the date range (e.g. December?)

I was using the measure below however this is not working as I want the user to be able to look at prior months based on the dates selected in the slicer.

Sales last month = Calculate(sum('sales'), FILTER(Date_DIM,month(Date_DIM[FullDate])=MONTH(today())))

Ive also tried the following but its not working (I have a relationship between date table and sales)

Lastmonth_Sales =

VAR LastMonth = max(Date_DIM[YYYY-MM])

VAR LastMonthsRESULT = CALCULATE(sum('sales'),LastMonth)

RETURN

LastMonthsRESULT

When I check whether the last month measure works, its selects the correct month, however the above measure is giving me an error message.

Any help would be greatly appreciated.

Thanks

[Natty_008 · Accepted solution]

Solved the query - here's my updated measure

NEW_Sales =

VAR LastSelectedMonth = Max(Date_DIM[YYYY-MM])

VAR LastMonthResult = 

Calculate(sum('Sales'[Sales]), 

FILTER(ALL(Date_DIM),

Date_DIM[YYYY-MM]=LastSelectedMonth

)

)

RETURN

LastMonthResult