Add data in between Simple Form association members

[why-el]

Hey there,

I am trying to use Simple Form's association to list a bunch of radio buttons like so: 

  <%= simple_form_for(@applicant) do |f| %>    

    <%= f.association :track, :as => :radio_buttons %>

  <% end %>

Assuming each track has many courses, how can I take every track from that association and loop over its courses to display them below the radio button? After all applicants need to know what each track has. 

Best,