Extended Search lets you search through your Jira instance using JQL with the additional functions included with JQL Search Extensions for Jira.
...
You can use additional functions provided by JQL Search Extensions. For example, to find all issues with a summary starting with “Hello”, type issue in wildcardMatch("summary", "Hello*").
...
...
Save the query as a filter
You can save your Extended Search query as a Jira filter. After you perform your search, clickSave the query as a filter.
See Extended Search filters to learn more about using and sharing filters.
Extended Search JQL functions
Here is For a full list of extensions, including examples, see JQL functions and keywords that you can use in Extended Searchreference.
Permissions and feature availability
...