someone PRO said almost 3 years ago on Nested Forms from Scratch with StimulusJS :

Any idea's how to get a second nested form's fields in the _task_fields partial to render?  in this example the nested car_field doesn't display on the main _form. 


# _task_fields.html.erb
<div class='nested-fields'>
  <div class='form-group'>
    <%= form.hidden_field :_destroy %>
    <%= form.text_field :description, placeholder: 'Description', class: 'form-control' %>
           <%= form.fields_for :car do |car_field| %>
              <%= car_field.text_field :engine%>
           <% end %>
    <small>
      <%= link_to "Remove", "#", data: { action: "click->nested-form#remove_association" } %>
    </small>
  </div>
</div>