How do I filter close epics with stories not closed

[Tammy Lloyd]

I want to filter close Epics in a project that have stories or bugs that are not closed.

So fare I have 

Filter = "project name" and issuetype = epic and status in ("closed")

How do I pick out stories/bugs that are not closed 

[Mirek]

Well, not quite sure which hosting type you are using (Cloud or On-Prem) and what kind of addons you have installed but it might be hard using native JQL functions. It is a lot easier when having Script Runner

Examples:

https://scriptrunner.adaptavist.com/latest/jira/jql-functions.html#_issuesinepics

Find unresolved stories in resolved epics:

issueFunction in issuesInEpics("resolution is not empty") and resolution is empty