gistfile1.scala

for {
  (k, v) <- tiers
  n <- filteredData if (n \ "metricPath").text.contains(v)
} yield k -> bts.filter(n \ "metricPath".text.contains).foldLeft(List[Transaction]()) {
  case (agg, bt) => {
    val trans = Transaction(bt, k)
    trans.metricData = Metric(n)
    bt :: agg
  }
}