tap/app/views/orders/new.html.erb

<ul class="users">
  <% @users.each do |user| %>
    <li>
      <%= form_for overview_path do |f| %>
        <%= hidden_field_tag 'user_id', user.id  %>

        <%= f.submit user.name , class: "btn btn-primary" %>
      <% end %>
    </li>
  <% end %>
</ul>