Encore\Admin\Grid\Filter\AbstractFilter::buildRelationCondition PHP Method

    protected function buildRelationCondition()
    {
        $args = func_get_args();
        list($relation, $args[0]) = explode('.', $this->column);
        return ['whereHas' => [$relation, function ($relation) use($args) {
            call_user_func_array([$relation, $this->query], $args);
        }]];
    }