@John Huebner thanks for answer. But i dont understand exacly what i must do. Do you have some example code for this. Then i can do if i saw some exmpale code. For now i have on custom template this:
acf_form(array(
'id' => 'acf-form',
'post_id' => 'new_post',
'post_title' => true,
'new_post' => array(
'post_title' => 'new_narocilnice',
),
and also i have already filter function my_pre_save_post( $post_id ) { ....
but i dont know what i must check in filter and how then save all custom field.