Guide on adding new fields for BKPF and BSEG on FB01/02/03

[xiswanto]

Hello,

I would like to request for any link on how to add new input field(s) in FB01/02 while also displaying them on FB03 on both:
- Header, and
- Item level.

Currently using the version SAP EHP 7 ERP 6.

So far, I've tried to add new field in BSEG item level by:
1. maintaining the new field in SPRO->FI->...->Ledger->Fields->Customer Fields-> Edit Coding Block, adding the new field in 'Customer include structure' of CI_COBL, then
2. appending a structure in BSEG that include the CI_COBL structure.

As a result, I could see this field shown on FB02 / FB03 in the second screen of OO ALV, but what I wanted was for the new field to show in the detail screen where I double click on one of the item row to show the detailed row information and make the value modifiable.

image a ( custom field item level on document main screen )

image b ( yellow block, where I expect the additional field show up or the screen after the button is pressed )

This steps work for me for tcode FB60 and the field is modifiable ( although it is limited to 5 additional fields only, starting from the sixth additional field are not diplayed on screen )

Also, I have not tried yet for the header level and I have no idea how to do so, but I would like to make some documentation about it in future requirement.

Any explanation or link is greatly appreciated.

Regards,

Siswanto