Crystal Reports Linking fields! SQL DB

Message

   Hi Everyone,

i have ran into an issue about linking 3 fields in 2 stored procedures , 
I have a stored procedure called 'MasterService' in which there are 2 fields:
MasterServices
Checklist

I have another stored procedure called 'Trainers' in which i have a field as:
TrainerName

now i want them to link as below logically :

TrainerNamer
     MasterService:( masterservice only which is associated with above trainer )
            -Checklist ( Checklist only which is associated with that masterservice )

I am using CR 2008 with SQL database , i tried linking with database expert but it does not give me result as above .

the field 'checklist' prints all the checklists weather its relevant to above field or not .

can achieve that using a formula ?

Thanks in Advance guys
Regards
Server_Sap