How configure logstash in Kubernetes to point to a specific directory that is mapped as emptydir or local

hello all
i need to configure logstash to listen to incoming logs in a directory. (which will be manually uploaded logs to )
And to process them and show them in kibana .
i already have filebeat monitoring running the apps that are running which sending to elasticsearch and then they presented in kibana And i don't what to disturb them .
All this is Kubernetes
so i will have something like this

Upload file to /tmp/log/subdirectorys/* ---> logstash listen and process them , send to ->  elasticsearch , send to -> kibana