matrix for next three year data

IF , You can use relative date slicer

https://docs.microsoft.com/en-us/power-bi/visuals/desktop-slicer-filter-date-range

 

or refer to this approach https://www.youtube.com/watch?v=duMSovyosXE

Hi, IF 

Since your "year" column is of text type, it is recommended to create a date type "year" column first：

 

Year(Date) = IF(ISERROR(DATE('Table'[Year],1,1)),BLANK(),DATE('Table'[Year],1,1))

 

Then  please try measure as below t0 replace the original field "Value1":

 

value2 = 
VAR _sel =
    SELECTEDVALUE ( 'Table'[Month] )
VAR _year =
    VALUE ( RIGHT ( _sel, 4 ) )
VAR b =
    CALCULATE (
        SUM ( 'Table'[Value1] ),
        FILTER (
            'Table',
            YEAR ( 'Table'[Year(Date)] ) <= _year + 2
                && YEAR ( 'Table'[Year(Date)] ) >= _year
        )
    )
RETURN
    IF ( ISFILTERED ( 'Table'[Month] ), b, SUM ( 'Table'[Value1] ) )

 

Then result will show as below:

Please check attached pbix file for more details.

 

For you Second question, I'm afraid that it‘s  impossible to add BP value to the end of the matrix.You need to create another table visual to  show it.

 

Best Regards,
Community Support Team _ Eason