Firelens/Fluentbit Multiple Output based on log regex

Question

I'm starting to use firelens/fluentbit and I'm trying to send my ECS task logs to different outputs (Opensearch index) based on some tag or string of the log. I saw the example of multiple destinations, and I was able to filter the logs by regex, but I didn't find any example of how to route based on a tag or string of the log to different OpenSearch index.