How to Update Custom fields in MSEG with MIGO through MB_MIGO_BADI

Hi All,

I have to Update Custom fields in MSEG table after getting them from user in MIGO transaction. I am using BADI--> MB_MIGO_BADI for this. There is method called POST_DOCUMENT in BADI but it is having MSEG as importing parameter. Also, How can i send my custom fields to BADI.

Thanks & Regards,

Bhargav D.