Dear Tanmoy,
As Thomas wrote a determination is likely going to fill that attribute. This determination will be implemented in ABAP and not everything you can implementent in that language may be expressed in SQL (at least not easily or you might need stored procedures).
However, in order to know what to do, you can make a where-used on the attribute you're looking for on the BO's constant interface. This will at least take you to the place where it's being manipulated.
Imperative programming rocks 
Cheers,
Oliver