Can I somehow access my property instance to build indexes dynamically?

property.rb

class Property < ActiveRecord::Base

  has_many :agents

  searchable do
    agents.each do |scoped_agent|
      string "sort_agents_#{scoped_agent.id}" do
        reordered_agents = agents.select { |agent| scoped_agent != agent }
        reordered_agents << scoped_agent
        reordered_agents.collect do |agent|
          agents.last_name_first
        end.join(' ').gsub(/,/, '')
      end
    end
  end
end