Get the previous row value in OBIEE 11g

Way of getting a value of the previous row: Use MSUM (MovingSum)

Actuals: "MCSR"."Actuals PJTD"

Previous Actuals:  MSUM("MCSR"."Actuals PJTD",2) - "MCSR"."Actuals PJTD"

This is similar to database level sql statement
select
empno,(sum(empno) over (order by 1 rows between 0 preceding and 1 following)-empno)
from emp;

Try this.....