Sort Key 014 even if you assigned in Vendor Master Data, it will not display PO Document in FBL1N, since FBL1N contains entries pertaining to Posting Keys 21 or 31 and so on but not the GRIR related posting keys which are 86 and 96. Please use FBL3N and enter your GR/IR Account. When you are on the report screen you can add following fields:
1. Offsetting Account
2. Offsetting Account Type
3. Offsetting Account Text
For Offsetting Account Type - Filter it with Acct Type K
Then you can also do subtotal with Offsetting Account and save the variant. This way you would be able to see the vendor name with a PO Document.
You should get PO number on vendor account with using FBL1N. But you must do some developments for it.
I wrote message how can you add additional field in FBL1N before message below.
But you can update PO field on vendor line items display.
You can skip adding field section on message which I gave you above.
You must copy from SAMPLE_INTERFACE_00001650 to ZFI_INTERFACE_00001650 FM and some customizing for updation BTE. I specified it on message.
Then you'll write some ABAP for PO number update in vendor line items.
I'm giving to you some examples below.
TABLES : bkpf, bseg. e_postab = i_postab. IF sy-tcode EQ 'FBL1N'. SELECT SINGLE * FROM bkpf WHERE bukrs = i_postab-bukrs AND belnr = i_postab-belnr AND gjahr = i_postab-gjahr. IF sy-subrc EQ 0. IF bkpf-awtyp EQ 'RMRP'. SELECT SINGLE * FROM bseg WHERE bukrs = i_postab-bukrs AND belnr = i_postab-belnr AND gjahr = i_postab-gjahr AND ebeln NE space. IF sy-subrc EQ 0. e_postab-ebeln = bseg-ebeln. ENDIF. ENDIF. ENDIF. ENDIF.