Search using "Region" field in Epics for board

[BMac]

I have a board that is across multiple projects. I have set regions in Epics and now would like to create a region based set of boards. Each board might be just one region or multiple. What is the query to return only Jiras in Epics that are in certain regions? 

[Tarun Sapra]

You use the right JQL filter for this purpose. Each Jira board is showing issues based on the underlying JQL filter thus you can modify/create an JQL filter to include the Region you want to show, for example

project =ABC and type = epic and Region = Sydney

This gives epics which have Region set as Sydney, now you can use this has filter and configure this filter in your boards and each board can have it's own filter having it's own Region.