Can we access paragraph field in views-view-unformatted.twig?
I don't think you can get the value of field from paragraph field inside views-view-unformatted.twig all you can get is the target_id of referenced paragraph using view.result[key]._entity:

I suggest to use template_preprocess_views_view_unformatted like the following:

function YOURTHEME_preprocess_views_view_unformatted(&amp;$variables) {
  $view = $variables['view'];
  $rows = $variables['rows'];
  if ($view-&gt;id() === 'YOUR_VIEW_ID') {
    $paragraph_storage = \Drupal::entityTypeManager()-&gt;getStorage('paragraph');
    foreach ($rows as $id =&gt; $row) {
      /** @var \Drupal\node\Entity\Node $node */
      $node = $view-&gt;result[$id]-&gt;_entity;
      // Get paragraph field.
      // Change field_paragraph by your filed ref to paragraph.
      if ($node-&gt;hasField('field_paragraph')) {
        $paragraph_ref_id = $node-&gt;field_paragraph-&gt;getValue()[0]['target_id'] ?? NULL;
        if ($paragraph_ref_id) {
          /** @var \Drupal\paragraphs\Entity\Paragraph $paragraph_entity */
          $paragraph_entity = $paragraph_storage-&gt;load($paragraph_ref_id);
          // Get the value of your field.
          // Change field_paragraph_text by your field.
          // And set another variable to use in twig.
          $variables['rows'][$id]['should_display_row'] = ($paragraph_entity-&gt;field_paragraph_text-&gt;value !== NULL) ? TRUE : FALSE;
        }
      }
    }
  }
}


Now in your views-view-unformatted.twig you can check on row.should_display_row like the following:

{% for row in rows %}
  {%
    set row_classes = [
      default_row_class ? 'views-row',
    ]
  %}
  {% if row.should_display_row %}
    &lt;div{{ row.attributes.addClass(row_classes) }}&gt;
      {{- row.content -}}
    &lt;/div&gt;
  {% endif %}
{% endfor %}