Rails nested_form gem updates wrong parent data - ruby-on-rails

Question

I have the following in one of my forms. With this code I can dynamically add divisions, sub_divisions and sub_sub_divisions on the page. The problem is the sub_sub_divisions I add are saved to the first sub_division even though they are correctly displayed on other sub_divisions on the view. I don't know what is happening between the view and what is passed to controller to make this error. Thanks a lot.
<%= nested_form_for #division do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<table>
<tr>
<td>
<%= f.label t("name") %>
<%= f.text_field :name, class: 'form-control' %>
</td>
<td>
<%= f.label t("description") %>
<%= f.text_field :description, class: 'form-control' %>
</td>
</tr>
<tr><td><h3><%=t :sub_divisions %></h3></td></tr>
<tr>
<td colspan=4>
<table id="sub_divs" class="table table-condensed table-striped">
<tr><th><%=t :name %></th><th><%=t :description %></th></tr>
<%= f.fields_for :sub_divs, :wrapper => false do |sub_div| %>
<tr class="fields">
<td><%= sub_div.text_field :name, class: 'form-control' %></td>
<td><%= sub_div.text_field :description, class: 'form-control' %></td>
<td><%= sub_div.link_to_remove t("delete") %></td>
</tr>
<td colspan=3>
<table id="<%= 'sub_sub_divs' + sub_div.index.to_s %>">
<tr><th><%=t :name %></th><th><%=t :description %></th></tr>
<%= sub_div.fields_for :sub_sub_divs,
:wrapper => false do |sub_sub_div| %>
<tr class="fields">
<td><%= sub_sub_div.text_field :name,
class: 'form-control' %></td>
<td><%= sub_sub_div.text_field :description, class:
'form-control' %></td>
<td><%= sub_sub_div.link_to_remove t("delete") %></td>
<td><%= sub_sub_div.hidden_field :id,
value: sub_sub_div.object.sub_div_id %></td>
</tr>
<% end %>
</table>
</td>
</tr>
<tr>
<td colspan=3 class="pull-right">
<%= sub_div.link_to_add t("add") +
t("sub") + t('sub') + t('div'), :sub_sub_divs,
:data => { :target => "#"+"sub_sub_divs" +
#{sub_div.index.to_s}", id: sub_div.object.id} %>
</td>
</tr>
<% end %>
</table>
</td>
</tr>
<tr><td colspan=2 class="pull-right">
<%= f.link_to_add t("add") + t("sub") + t('div'),
:sub_divs, :data => { :target => "#sub_divs"} %></td></tr>
<tr><td><%= f.submit t("update"), class: "btn btn-primary" %></td></tr>
</table>
<% end %>

Answer 1

Outside of your call to
<%= f.fields_for :sub_divs, :wrapper => false do |sub_div| %>
You should iterate over the sub_divs:
<%= #division.sub_divs.each do |sub_div| %>
And then pass each one to the fields_for call as the 2nd parameter:
<%= f.fields_for :sub_divs, sub_div, :wrapper => false do |sub_div| %>
Do the same for the next nested sub_sub_div and finally:
<%= sub_sub_div.hidden_field :id,
value: sub_sub_div.object.sub_div_id %>
...will have the correct sub_div_id