app/views/backend/notas/_edit_form.html.erb
<%= simple_form_for [:backend, resource] do |f| %>
<%= f.input :numero, :label =>"Numero" %>
<%= f.association :organization, input_html: {class: 'select2'}, label: "Tipo de iniciador" %>
<%= f.simple_fields_for :initiator do |initiator_form| %>
<%= initiator_form.input :name, :label => "Iniciador" %>
<% end %>
<%= f.association :tags, input_html: {multiple: true, class: 'chzn-select',
"data-pre" => f.object.tags.to_json(methods: :name), only: [:id, :name]} %>
<br>
<%= f.submit %>
<% end %>