Can the more fields dropdown on filter be overridden?

[Phil Manser]

We have a custom field that has several different (yet similar) contexts. When a user is searching issues across all projects and clicks on the More dropdown our custom field is unavailable. If the user limits their search to projects that have the same context of the custom field, then the field becomes available.

Is there a way to override this behavior? We'd like to have the custom field be available at all times and then handle any contextual differences within the code. 

[Phil Manser · Accepted solution]

I finally figured this out so I'm documenting it here in case anyone else needs it.

In the Searcher defined for your custom field you'll need to override the SearchRenderer returned by getSearchRenderer(). In your custom SearchRenderer you'll need to override what is returned by the isShown method.