app/views/serials/show.html.erb
<%= content_for :report do -%>
<ul class="no_bullets">
<%= content_tag(:li, link_to('Similar serials', similar_serials_task_path(@serial))) %>
</ul>
<% end %>
<%= content_for :additional_navigation do %>
<% unless @serial.all_previous.empty? %>
<div class='content'>
<h3>Preceeding</h3>
<ul class="no_bullets">
<% @serial.all_previous.flatten.each do |ps| %>
<li><%= object_link(ps) %></li>
<% end %>
</ul>
</div>
<% end %>
<% unless @serial.all_succeeding.empty? %>
<div class='content'>
<h3>Succeeding</h3>
<ul class="no_bullets">
<% @serial.all_succeeding.flatten.each do |ps| %>
<li><%= object_link(ps) %></li>
<% end %>
</ul>
</div>
<% end %>
<% end %>
<%= render(partial: 'shared/data/project/show', locals: {object: @serial}) -%>