Logstash configuration : 6.3

If you use this output (below) you will see which field Filebeat puts the path in, alternatively, there may be some other field's value, that Filebeat fills in, that you can use to identify which events are in which format.

output {
  stdout { codec => rubydebug { metadata => true } }
}

then use if conditionals to "steer" the events to their filters. Docs here.