Buongiorno,
con il mio tema di drupal avrei la necessità di modificare il blocco del menu di navigazione principale,
dato che in tale blocco devo associare due menu. Ho creato un'altra regione dove inserisco il secondo menu
e posizionata nel file della navbar. Ora però avrei bisono di avere un codice html come il template seguente
per quanto riguarda il mega menu..

https://italia.github.io/bootstrap-italia/docs/esempi/template-comuni-vu...

Da come ho capito devo modificare il file block--system-menu-block--main.html.twig del mio tema
che ha il seguene codice:

{#
/**
* @file
* Theme override for a menu block.
*
* Available variables:
* - plugin_id: The ID of the block implementation.
* - label: The configured label of the block if visible.
* - configuration: A list of the block's configuration values.
*   - label: The configured label for the block.
*   - label_display: The display settings for the label.
*   - provider: The module or other provider that provided this block plugin.
*   - Block plugin specific settings will also be stored here.
* - content: The content of this block.
* - attributes: HTML attributes for the containing element.
*   - id: A valid HTML ID and guaranteed unique.
* - title_attributes: HTML attributes for the title element.
* - content_attributes: HTML attributes for the content element.
* - title_prefix: Additional output populated by modules, intended to be
*   displayed in front of the main title tag that appears in the template.
* - title_suffix: Additional output populated by modules, intended to be
*   displayed after the main title tag that appears in the template.
*
* Headings should be used on navigation menus that consistently appear on
* multiple pages. When this menu block's label is configured to not be
* displayed, it is automatically made invisible using the 'visually-hidden' CSS
* class, which still keeps it visible for screen-readers and assistive
* technology. Headings allow screen-reader and keyboard only users to navigate
* to or skip the links.
* See http://juicystudio.com/article/screen-readers-display-none.php and
* http://www.w3.org/TR/WCAG-TECHS/H42.html for more information.
*/
#}
{% import '@bootstrap_italia/macros.twig' as macros %}
{% set heading_id = attributes.id ~ '-menu'|clean_id %}

<nav
  role="navigation"
  aria-labelledby="{{ heading_id }}"
  {{ attributes.addClass(['navbar','navbar-expand-lg','has-megamenu'])|without('role', 'aria-labelledby') }}
>
  <button class="custom-navbar-toggler" type="button" aria-controls="{{ heading_id }}" aria-expanded="false" aria-label="Toggle navigation" data-target="#{{ heading_id }}">
    {{ macros.icon('it-burger', base_path ~ directory) }}
  </button>
  <div class="navbar-collapsable" id="{{ heading_id }}" style="display: none;">
    <div class="overlay" style="display: none;"></div>
    <div class="close-div sr-only">
      <button class="btn close-menu" type="button"><span class="it-close"></span>{{ 'Close'|trans }}</button>
    </div>
    <div class="menu-wrapper">
      {# Label. If not displayed, we still provide it for screen readers. #}
      {% if not configuration.label_display %}
        {% set title_attributes = title_attributes.addClass('visually-hidden') %}
      {% endif %}
      {{ title_prefix }}
      <h2{{ title_attributes.setAttribute('id', heading_id~'-title') }}>{{ configuration.label }}</h2>
      {{ title_suffix }}

      {# Menu. #}
      {% block content %}
        {{ content }}
      {% endblock %}
    </div>
  </div>
</nav>

La mia domanda è come lo devo modificare per dargli una struttura come quella del template del link ?
E richiamare il rendering delle due regione dei menu correttamente ?
Grazie mille