How to call subfields in Twig (from .yaml file)

Hello there.

I’m changing a particle of Gantry framework, with Grav. I have the .yaml file with the following code:

items:
      type: collection.list
      array: true
      label: Tab Items
      description: Create each tab to display.
      value: name
      ajax: true
      fields:
        .member:
          type: input.imagepicker
          label: Member Image
        .position:
          type: input.text
          label: Position
        .socials:
          type: collection.list
          label: Social Links
          array: true
          value: name
          ajax: true
          fields:
            .social_text:
              type: input.text
              label: Social Text
            .social_link:
              type: input.text
              label: Social Link

In Twig template I have:

{% for item in particle.items %} 
     <div class="person-name">
         <h3>{{item.name_member}}
     </div>
     <div class="person-position">
        {{item.position}}
    </div>
    <div class="person-social">
        {% for item in particle.socials %}
           <a target="_blank" href="{{item.link}} aria-label="{{item.text}}"><i class="{{item.icon}}"></i></a>
         {% endfor %}
    </div>

In Layout.yaml file I have:

items:
        -
          member: 'gantry-media://member-man..png'
          position: Something
          name_member: Anybody
          socials:
            -
              social_text: Facebook
              social_link: 'https://facebook.com'
              social_icon: 'fa fa-facebook'
              name: facebook
          name: Anybody

The question is How can I call to socials items from Twig template?. I’ve tried some alternatives (for item in particle.socials, for item in particle[’.socials’], for social in socials). I don’t know how can I do it.

Can anybody help me?
Thanks in advance.