Kibana filtering percentile/outliers

There is no way of doing this without some manual steps. You could have a metric visualization that shows the 99%, 90%, and 50% duration values. Then you could manually create a lucene query that filters the data to be above that value to view the targeted documents.

Doing this in an automated way is an interesting usecase. I would recommend opening a enhancement issue at https://github.com/elastic/kibana/issues to track the idea.