Certain GL Account Posting might be repeated, you can do a copy of the posting entry and only key in the amount that are always different.

e.g.              Dr          12345                 100
                   Dr          45678                   50
                   Cr          98765                  150

Steps:-

• go to transaction FKMT - Account Assignment Model
• Key in the Act Assignment mode e.g.  XYZ - Names related to the Entry
• Click Goto -> Line items
• Key in the DR/CR enteris. company code, GL account, TX, BA, Cost Center etc.
• Save

• Click the Act Assignment model button

Filled in the Act Assignment mode Names and hit enter to update the entries