Problem with FM REUSE_ALV_BLOCK_LIST_APPEND for saving layout

In my program, user wants to show 4 alv list on same screen so i use FM REUSE_ALV_BLOCK_LIST_APPEND to show them.

but i have a problem that ALV list can adjust the layout but can not save.

when i go to see into the FM there is no parameters

i_save = .....

is_variant = .....

like REUSE_ALV_LIST_DISPLAY

Functional Consultant showed me T-Code: FBL5N that the standard can do so u also can do !

when i debugged the standard , it use REUSE_ALV_LIST_DISPLAY (in FM FI_ITEMS_DISPLAY)

but i can't copy it coz it's too complicated.

How do I solve this problem ?

Thanks in advance