foo.md

old view

<%= select_for_tag :name,
  options_for_select(complex.stuff.collect{|d| d.stuff} + ['other', 'stuff']) %>

new view

<%= select_for_tag :name,
  options_for_select(complex.stuff.collect{|d| d.stuff} + admin_selection_choices(user) + ['other', 'stuff']) %>

helper method

def admin_selection_choices(user)
  if user.admin
    ['admin', 'choices']
  else
    []
  end
end