How to get a list of stories in set of epics from query?

[MargaretT]

This seems like it should be easy but getting syntax errors.

I have labeled some epics with a label "X" and I want to query for all stories related to those epics without having to specify the individual epics. 

"Epic Link" in (project = MyProject AND issuetype = Epic AND labels = X)

If I run just the query within the parentheses I get a list of the epics I want but adding the nesting am getting an error 

Error in the JQL Query: Expecting ',' or ')' but got '='. (line 1, character 26)

[Muhammad Ramzan(Atlassian Certified Master)]

This will not work you can rephrase it as 

Epic link in (epiclink1,epiclink2) 

With default JQL , you can get results by mentioning the epic links itself.

If you want to get issues results as you required then you need to use a third party plugin like JQL Search Extensions for Jira & reports 

issue in allIssuesInEpic("(project = MyProject") and labels=x and project=myproject

How it will work

Get all epics with labels x  from myproject and then get stories and sub tasks of these epics.