search_scope.rb

class Address
  # :street, String
  # :city, String
  # :state, String
  # :country, String

  scope :local, lambda { |query| search_by_street_or_city(query, query) }
  scope :national, lambda {|query| search_by_state_or_country(query, query) }
end

Address.national("Iceland") # => [<Address ...>]
Address.local("Iceland") # => []