我设法解决了这个问题。他是供进一步参考的解决方案。

1） 我现在只有1个查询变量：

function return_vars( $vars ) {
  $vars[] = \'filters\';
  return $vars;
}

add_rewrite_rule( \'my-base/filters/([^\\/]*)/([^&]*)/page/([0-9]{1,})/?\', \'index.php?post_type=$matches[1]&filters=$matches[2]&paged=$matches[3]\', \'top\');
add_rewrite_rule( \'my-base/filters/([^\\/]*)/([^&]*)/?\', \'index.php?post_type=$matches[1]&filters=$matches[2]\', \'top\');

他们必须按这个顺序。

3） 然后，我或多或少地以这种方式过滤过滤器字符串

function my_pre_get_posts( $query ) {
  $filters = get_query_var(\'filters\');

  // if no filter or if filters are odd, then return
  if(!$filters || count(explode("/", $k4w_filters)) % 2 != 0) return;

  // this is a global array with my 2 tax slugs in it
  global $CUSTOM_TAXES_S;

  $chunks = array_chunk(explode(\'/\', $filters), 2);
  $filter_data = array_combine(array_column($chunks, 0), array_column($chunks, 1));

  // filter data, populate tax_data and field_data for queries
  foreach($filter_data as $key => $value) {
    if(in_array($key, $CUSTOM_TAXES_S)) {
        $tax_data[$key] = $value;
    } else {
        $field_data[$key] = $value;
    }
    $query->set(\'debug_tax_data\', $tax_data);
    $query->set(\'debug_field_data\', $field_data);
  }

  // if tax_data exist set tax_query
  if($tax_data) {
    foreach( $tax_data as $taxonomy => $slugs ) {
        // append tax query
        $tax_query[] = array(
            \'taxonomy\'  => get_tax_name($taxonomy), // that\'s a simple function that retrieves the taxonomy name from its slug
            \'field\'     => \'slug\',
            \'terms\'     => explode(\',\', $slugs),
        );
    }
    $query->set(\'tax_query\', $tax_query);
  }

  // if field_data exist set meta_query
  if($field_data) {
    foreach( $field_data as $key => $value ) {
        // append tax query
        $meta_query[] = array(
            \'key\'   => $key,
            \'value\'     => explode(\',\',$value),
            \'compare\'       => \'IN\',
        );
    }
    $query->set(\'meta_query\', $meta_query);
  }
}
add_action(\'pre_get_posts\', \'my_pre_get_posts\', 10, 1);

/my-base/filters/my-cpt/tax1/term1,term2/tax2/term1,term2/field1/val1,val2/goingon...

显然，上面的代码是可行的，但也有一些检查可以避免问题和黑客攻击（例如检查提供的字段名是否存在，或者是否在可过滤字段列表中等等）。

希望这对某人有所帮助：）