FMBSEG is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "FI documents" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_FMBSEG TYPE FMBSEG.
The FMBSEG table consists of various fields, each holding specific information or linking keys about FI documents data available in SAP. These include REBZG (Number of the Invoice the Transaction Belongs to), REBZJ (Fiscal Year of the Relevant Invoice (for Credit Memo)), REBZZ (Line Item in the Relevant Invoice), ZUONR (Assignment Number)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .
