obtener los valores de los select anidados

app/views/posts/template_field/_select.haml

@@ -1,5 +1,10 @@
+- if name.is_a?(Array) && name.count == 3
+  - value = @post.get_front_matter(name.first).try(:[], name.second.to_i).try(:[], name.last)
+- else
+  - value = @post.get_front_matter(template.key)
+- values = template.values.empty? ? value : template.values
 = select_tag field_name_for_post_as_string(name),
-  options_for_select(template.values, @post.get_front_matter(template)),
+  options_for_select(values, value),
   { class: 'form-control select2',
   multiple: template.multiple?,
   required: template.required?,