Inside of JIRA Cloud, you can only use the issueFunction() JQL function provided by ScriptRunner on the Enhanced Search page as described in the documentation here and will get an error of issueFunction is not found if you try and use the issueFunction() JQL function inside of the standard Jira Search feature.
This is due to the way that Atlassian restrict how the JQL functions can interact with their infrastructure meaning we must run them in a sandbox process.
However this does not mean that they cannot be used inside other filters or on filters for Agile boards, and to use the functions in other filters then you will need to follow the steps outlined below.
- Navigate to the enhanced search page and construct the filter you require using the JQL functions provided by ScriptRunner.
- Save your filter and share it with the users that are required to be able to see it.
- Create the JQL search used by your board filter or quick filter and reference the saved filter using the syntax shown below which will return the results of your filter using the JQL functions provided by ScriptRunner.