Suppression in SAP Pi 7.1

Hi Experts,

I have the requirement where BUSAB field in E1KNB5M segment should be populated only when MAHNA(E1KNB5M) segment exists and not null.

FYI: BUSAB field exists in both the E1KNB1M and E1KNB5M segment and the values will be same. I have used create if and target is not getting created.

Please advice.