Scala multi-level pattern matching

I'm stuck with multi-level pattern matching, in the code below I want to match one particular case which is checked at several levels "cfe is Assignment, assignmentCfe.getRight is BinaryExpression, and so on", the solution looks ugly and I hope there is something better Scala can offer me. :)

  def findAll(cfg: Cfg, consumer: Consumer[Violation]): Unit = {
    val fa = new FlowAnalyzer
    val states = fa.analyze(cfg)

    states.foreach { case (cfe, state) => cfe match {
      case assign: Assignment => assign.getRight match {
        case expression: BinaryExpression => expression.getOperator match {
          case Operator.Div | Operator.Rem => processDivisions()
          case _ =>
        }
        case _ =>
      }
      case _ =>
    }
    case _ =>
    }
  }

How to get rid of these empty default cases in the end?

Another approach would be using nested conditions, but IntelliJ IDEA offers me to replace these conditions back to pattern matching

states.foreach { case (cfe, state) => if (cfe.isInstanceOf[Assignment]) {
      val assignment = cfe.asInstanceOf[Assignment]
      if (assignment.getRight.isInstanceOf[BinaryExpression]) {
        val expression = assignment.getRight.asInstanceOf[BinaryExpression]
        if (expression.getOperator == Operator.Div || expression.getOperator == Operator.Rem) processDivisions()
      }
    }}