<% f.fields_for :order do |order_form| %>
  <% order_form.fields_for :checkout do |checkout_form| %>

    <% checkout_form.fields_for :bill_address do |ba_form| %>
      <%= render :partial => 'spree/admin/shared/address_form', :locals => { :f => ba_form, :name => t(:billing_address) } %>
    <% end %>

  <% end %>
<% end %>
