Scenario: two selectors both with days. User chooses Tuesday in one, Friday in the other. I need to assemble the days Tuesday through Friday as an array and display them all in the view. I store the selection data as first_day_id and last_day_id, but I can not figure out or find an example of how to assemble them as an array for the view.

_form.html.erb

<%= simple_form_for(report) do |f| %>
    
  <%= f.input :first_day_id, collection: Week.all, as: :grouped_select, group_method: :days %>
  <%= f.input :last_day_id, collection: Week.all, as: :grouped_select, group_method: :days %>
    
  <%= f.button :submit, class: "btn-primary" %>
<% end %>