Can't read the data from 2nd level nested attribute in ActiveAdmin <p><em>I have 3 classes:</em></p> <p><strong>app/model/order.rb</strong></p> <pre><code>class Order &lt; ActiveRecord::Base has_many :lines, dependent: :destroy accepts_nested_attributes_for :lines, allow_destroy: true end </code></pre> <p><strong>app/model/line.rb</strong></p> <pre><code>class Line &lt; ActiveRecord::Base belongs_to :order has_many :picklines, dependent: :destroy end </code></pre> <p><strong>app/model/pickline.rb</strong></p> <pre><code>class Pickline &lt; ActiveRecord::Base belongs_to :line end </code></pre> <p>So, from the above, the structure as follows <code>Order&gt;Line&gt;Pickline</code>, i.e. <code>Pickline</code> will be 2nd level nested attrubte to <code>Order</code>.</p> <p>I was able to read the column from <code>Line</code> (1st level nested) as below:</p> <p><strong>app/admin/order.rb</strong></p> <pre><code>show do panel "Items" do table_for order.lines do column :description end end end </code></pre> <p>Now, I'm having headache on how to retrieve, for example, column named "quantity" from the 2nd level nested attribute of <code>Pickline</code>...</p> <p>I understand that I first have to iterate on each <code>Line</code> and then on each <code>Pickline</code> to retrieve any column from Pickline, but can't figure out how this can be done in ActiveAdmin.</p>