Marc,
what I had to add in addition to the code recommendation of SAP:
MODULE receive_data OUTPUT.
IF o_badi_fdcb_subbas05 IS INITIAL.
CALL METHOD cl_exithandler=>get_instance_for_subscreens
CHANGING
instance = o_badi_fdcb_subbas05
EXCEPTIONS
no_reference = 1
no_interface_reference = 2
no_exit_interface = 3
data_incons_in_exit_managem = 4
class_not_implement_interface = 5
OTHERS = 6.
CALL METHOD o_badi_fdcb_subbas05->put_data_to_screen_object
EXPORTING
im_invfo = invfo.
ENDIF.
CHECK NOT o_badi_fdcb_subbas05 IS INITIAL.
* get data from main screen
CALL METHOD o_badi_fdcb_subbas05->get_data_from_screen_object
IMPORTING
ex_invfo = invfo.
ENDMODULE. " RECEIVE_DATA OUTPUT
After that I got INVFO and the screen populated.