Dear Christian,
Thanks for your reply.
I have already created a validation rule for one to one relation G/L account--->Cost center.
But my objective is to restrict the posting @cost center level. When others tried to post through other G/L accounts to that particular cost center it should throw an error message.
Relationship should be
1GL account :1 cost center
2GL account :1cost center but not
NG/L account to 1 cost center.
Regards,
Mahesh