How to change the order of the sublists with wp_list_pages

Hello !
How can I make the list of pages that are for example after the 2nd level be ordered by menu_order and not as the first level by post_title.

I’ve read that this can be done with a walker but I can’t figure out how exactly to structure my algorithm to check what level the pages are.

Sometimes pages have years in their name and it’s complicated to order them all with menu_order.

Thank you for your cooperation ! I hope this question is useful to other people as well.