In this configuration activity you will specify an accounting object by which splitting will happen.
Transaction: S_AL0_19000071
IMG Path: Financial Accounting (New) -> General Ledger Accounting (New) -> Business Transactions -> Document Splitting -> Define Document Splitting Characteristics for General Ledger Accounting
Table: FAGL_SPLIT_FIELD
When you enter into the transaction, you get following screen. Create a new field characteristic or edit an already existing one.