Grafana Agent Flow - Get Label from Part of File Path

Please help me get a label from part of the file path using Grafana Agent Flow.

This is my non-working, feeble attempt:

local.file_match "xrc_sitechecker_xrc_eventlogs" {
  path_targets = [
    {__path__    = "/Users/1/Documents/3/Event Logs/Exported Event Logs/012/Event Logs/*.csv", "sitename" = "mysite", job = "eventlogs", "radiosystem" = "system1"},
  ]
}

loki.process "xrc_sitechecker_xrc_eventlogs" {
   forward_to = [loki.write.local.receiver]

   stage.regex {
      source_labels = ["__path__"]
      regex         = ".*/(?<site>[0-9]+)/Event Logs/.*\\.csv"
   }