Let's change this to:
```scala
(path, node) match {
  case (_, None) => null
  case (h::Nil, Some(fs)) => fs.get(h).orNull
  case (h::tail, Some(fs)) => fs.get(h).map { m => nestedRetrieval(Some(m), tail) }.orNull
  case (Nil, _) => null
}

```