dsfr4drupal-1.x-dev/layouts/layout_builder/layout--threecol-section.html.twig

{% set col_class1 = 'fr-col-lg-4' %}
{% set col_class2 = col_class1 %}
{% set col_class3 = col_class1 %}

{% for class in attributes.getClass() %}
  {% if '25-50-25' in class %}
    {% set col_class1 = 'fr-col-lg-3' %}
    {% set col_class2 = 'fr-col-lg-6' %}
    {% set col_class3 = col_class1 %}
  {% elseif '25-25-50' in class %}
    {% set col_class1 = 'fr-col-lg-3' %}
    {% set col_class2 = col_class1 %}
    {% set col_class3 = 'fr-col-lg-6' %}
  {% elseif '50-25-25' in class %}
    {% set col_class1 = 'fr-col-lg-6' %}
    {% set col_class2 = 'fr-col-lg-3' %}
    {% set col_class3 = col_class2 %}
  {% endif %}
{% endfor %}

{% if content %}
  <div{{ attributes.addClass('fr-grid-row', 'fr-grid-row--gutters') }}>
    {% if content.first %}
      <div {{ region_attributes.first.addClass('fr-col-12', col_class1) }}>
        {{ content.first }}
      </div>
    {% endif %}

    {% if content.second %}
      <div {{ region_attributes.second.addClass('fr-col-12', col_class2) }}>
        {{ content.second }}
      </div>
    {% endif %}

    {% if content.third %}
      <div {{ region_attributes.third.addClass('fr-col-12', col_class3) }}>
        {{ content.third }}
      </div>
    {% endif %}
  </div>
{% endif %}