class UsersController < ApplicationController

  before_filter :check_allowed_role,  :only => [:index, :destroy, :enable, :show]

....

#login_system.rb

  def check_allowed_role
    unless is_logged_in? && (@logged_in_user.has_role?('Administrator') || @logged_in_user.has_role?('Support'))
      flash[:error] = "You do not have the permission to do that."
      redirect_to :controller => 'account', :action => 'login'
    end
  end