Hi Maria,
that works. You Need to do the following:
1. Do not define a "normal" selection Screen in your ABAP as this just eliminates the Standard selection Screen.
2. Define your Selection Screen with:
SELECTION-SCREEN BEGIN OF SCREEN 100 AS SUBSCREEN.
Just as example: SELECT-OPTIONS: s_aufnr FOR caufv-aufnr.
SELECTION-SCREEN END OF SCREEN 100.
3. Create a normal Screen with 2 subscreen Areas (SUB1 and SUB2)
4. Create a normal Subscreen (e.g. 9001)
5. Add the following logic to the PBO area of the normal Screen created in 3.
CALL SUBSCREEN SUB1 INCLUDING sy-cprog '0100'.
CALL SUBSCREEN SUB2 INCLUDING sy-cprog '9001'.
It Needs to be explored how the PBO and PAI Events get triggered. But the Screen should as a starting Point look like you have described it.
Regards
Oliver