Here we would like to draw your attention to GGB1 transaction code in SAP. As we know it is being used in the SAP FI-SL (Special Purpose Ledger in FI) component which is coming under FI module (Financial Accounting). GGB1 is a transaction code used for Substitution Maintenance in SAP.
It comes under the package for Validation, Substitution and Rules (GVAL). When we execute this transaction code, RGMGBR20 is the normal standard SAP program that is being executed in background. Transaction code GGB1 is included in the SAP component for SAP_FIN.
Transaction GGB1 technical data table