title: Rails grouped_collection_select value_method with parameters
body: <p>Is there any way to use <a href="https://api.rubyonrails.org/v6.0.2.1/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-grouped_collection_select" rel="nofollow noreferrer">grouped_collection_select</a> <code>value_method</code> with parameters in Rails?</p>
  
  <p>I'm trying to filter out a couple of options based on the current_user (effectively using something like: <code>signed_by(current_user)</code>) but I'm having some difficulty passing it in.</p>
  
  <pre><code>&lt;%= f.grouped_collection_select :author_id, Author.posts, :signed_by, :title, :id, :email %&gt;
  </code></pre>
  
  <p>Any ideas?</p>