This document discusses how to filter messages from an ActiveMQ queue by JMS priority using Groovy script in Mule. It shows sending a message to the "StudioOUT" queue with a JMS priority of 9. Then it demonstrates consuming the message from the queue using a Groovy script filter to retrieve only the message with that priority of 9. The Groovy script allows filtering messages from the ActiveMQ queue by JMS priority when integrating with Mule.