Get the values of views fields in a Twig template
In the template file (views-view-field), you can use 

&lt;li&gt; {{ row._entity.field_name1.value }} {{ row._entity.field_name2.value }} {{ row._entity.field_name3.value }}&lt;/li&gt;


Or, in your theme, in the preprocess function you can overwrite the output:

function your_theme_name_preprocess_views_view_field(&amp;$variables) {
    $view = $variables['view'];
    if ($view-&gt;storage-&gt;id() == 'your_view_name') {
        $variables['output'] = '&lt;li&gt;' . 
          $variables['row']-&gt;_entity-&gt;field_name1-&gt;value . 
          $variables['row']-&gt;_entity-&gt;field_name2-&gt;value . 
          $variables['row']-&gt;_entity-&gt;field_name3-&gt;value . 
        '&lt;/li&gt;';
    }
}