Total previous value

Hey,

here you will find a PBIX file. This file contains a really small amount of sample data :-)

But besides that it's really close to your model.

I create these two measures:

A plus B = SUM(Table1[A]) + SUM(Table1[B]) 

and

PrevMonth A plus B = 
CALCULATE(
    [A plus B]
    ,PREVIOUSMONTH('Calendar'[Date])
)

Please be aware that I|m using the Calendar table in the measure to calculate the Previous Month Value.

As you can see from this screenshot both measure are recreating the primary issue, no sum for the total row

There is no value, because there is no active filter from the Calendar table.

For this reason, it's necessary to use SUMX() to iterate across the months.

The DAX statement for the measure I provided in my previous post was creating weird values due to the fact, the for each Day of the current month the previous month value was added.

For this it's necessary to iterate across the months and not the days.

Be aware that I'm using the column "Year-Month" from my Calendar table.

here is the measure:

SUMX PrevMonth A plus B = 
SUMX(
    VALUES('Calendar'[Year-Month])
    ,[PrevMonth A plus B]
)

And now it looks like this

 I would recommend that you change the relationship between your tables from 1:1 to 1 (your calendar table) to many (your fact table) and also adjust the filter direction from Both to Single, in most of the cases this is sufficient :-)

Hopefully this is what you are lookinf for

Regards

Tom