AutoObjectMembers.scala

object Settings {
  final val Host = "host"
  final val Protocol = "protocol"

  object User {
    final val Name = "username"
    final val Password = "password"
  }

  object Subject {
    final val Query = "query"
    final val Predicate = "predicate"
  }
}
//================================

def deepMembers[A: scala.reflect.runtime.universe.TypeTag](a: A) = {
  import scala.reflect.runtime.universe._

  def members(s: Symbol): Map[String, String] =
    s.typeSignature.declarations.collect {
      case m: ModuleSymbol => members(m)
      case m: MethodSymbol if m.isAccessor => m.returnType match {
        case ConstantType(Constant(s: String)) => Map(m.name.decoded -> s)
        case _ => Map.empty[String, String]
      }
    }.foldLeft(Map.empty[String, String])(_ ++ _)

  members(typeOf[A].termSymbol)
}

scala> deepMembers( Settings ) foreach println