Ember CLI Mirage: How to filter out return value?

This is how I get all data in config.js:

this.get('/rentals', function (schema, request) {
    if (request.queryParams.value) {
        // The code should be here...
    } else {
        return schema.rentals.all();
    }

}

I looked at documentation, but there's no way to get filtered ones. Apparently there are commands like all(), find(), findBy(), create(), etc. But there's nothing that filters out and returns. Any help?