You can either use layouts or structure your code in such a way that you can call a function to recalculate the sizes of the objects. Aside from layouts there’s no built-in solution for handling this, as needing to resize the screen is not a common requirement.
Looks like I’ve found a solution. I can create a page/cont/win based layout and then recalculate relative position on LV_SIGNAL_STYLE_CHG. Of cource after changing resolution I need to call lv_obj_refresh_style function.