Customer Group 1,2 fields in billing Doc. screen

Hi Gurus,

I have mapped some information about customers in customer group field like cust grp 1, 2,3,4,5 in the customer master data. \

While creating sales order, the same is copied into VBAK sales order header. But the same is NOT available in Billing document. Technicall, the fields are present in the table VBRP like  KVGR1, KVGR2, KVGR3, KVGR4, KVGR5.

The problem is that the fields are NOT visible in the screen VF02 item level. I hope you have understood my doubt.

I also checked the table LIPS - Delivery Item table, fields KVGR1,2,3,4,5 are present there too.

Any thing in Copy control VTFL from LF and F2. ?

Please suggest your valuable comments.

Regards,

Anbu