Year on Year not using Before()

[n1ef5ng1]

I need to compute year on year, month on month comparison using pivot table

However, I am unable to use Before() as it will list out all the dimension value even if it is null

example my dimension consist of country that has 240 fields

however there is only 50 fields that contains value in the country

By using Before(), it actually list out the 240 fields

My question is, is there any way i can substitute this code to prevent the year to minus another year that has no data/

=if( Before( Sum (IF(Derived_Status <> 'LRSHP', TEU,0)) , 12)  = 0

  OR IsNull( Before( Sum (IF(Derived_Status <> 'LRSHP', TEU,0)) , 12)) = -1, null(),

[n1ef5ng1]

any help