Write Post-Query trigger for the block you want to fetch the field value for display item.
Example
Begin
Select Ename into :datablock.dspname
from emp
where ecode = :datablock.ecode;
-- Field dspname in datablock will be populated with the value
exception
when others then
-- you can ignore error
null;
End;
You can write multiple plsql blocks in post-query trigger for different tables.
