Expose default search/filter function

[faizaaulia]

Expose the default search/filter function, so it still can be used to filter the options even the select in not searchable

For example, I add a search input in beforelist template then I want to apply the default filter function on user's search input, so I don't need to make a function to filter the options

Or is it already exposed? If it's already exposed, what's the function name?