Here the two programs which are calling dynamically.

REPORT ZSOURCE2309.
PERFORM EXTFORM IN PROGRAM ZSOURCE2310
USING 'CALL_BACK_FORM'
SY-CPROG.
FORM CALL_BACK_FORM.
WRITE / 'I am the call back form in ZSOURCE2309.'.
ENDFORM.

REPORT ZSOURCE2310.
FORM EXTFORM
USING F_CALL_BACK_FORM
F_PROGRAM.
PERFORM (F_CALL_BACK_FORM) IN PROGRAM (F_PROGRAM).
WRITE / 'I am the form in ZSOURCE2310.'.
ENDFORM.

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