对于不在给定类别子类别中的帖子，您需要进行第二次税务查询。要做到这一点，你需要获得孩子们的身份证。这是可能的get_term_children():

$args = [
    \'post_type\'      => \'post\',
    \'post_status\'    => \'publish\',
    \'posts_per_page\' => $post_number + 1,
    \'paged\'          => ( get_query_var( \'paged\' ) ) ? get_query_var( \'paged\' ) : 1,
    \'tax_query\'      => [
        [
            \'taxonomy\'         => $taxonomy,
            \'field\'            => \'term_id\',
            \'terms\'            => $category_id,
            \'include_children\' => false
        ],
        [
            \'taxonomy\' => $taxonomy,
            \'field\'    => \'term_id\',
            \'terms\'    => get_term_children( $category_id, $taxonomy ),
            \'operator\' => \'NOT IN\'
        ],
    ],
];