Complex QueryBuilder expresion in createQuery() with Sonata Admin - doctrine-orm

Question

I'm using Symfony 4.2 and Sonata Admin bundle and I'm trying to display a specific list in one of my admin list view.
I want to display the lastest user by group. I created the SQL query and I'm now trying to translate it to QueryBuilder.
SELECT * FROM users
WHERE (created_at, group_id) IN (
SELECT MAX(created_at), group_id
FROM users
GROUP BY group_id)
My createQuery function in my Sonata Admin class :
public function createQuery($context = 'list')
{
$container = $this->getConfigurationPool()->getContainer();
$em = $container->get('doctrine.orm.entity_manager');
$expr = $em->getExpressionBuilder();
$subQuery = $em->createQueryBuilder()
->select('MAX(c.createdAt), c.group')
->from('ApiBundle:Configuration', 'c')
->groupBy('c.group')
->getDQL();
$query = parent::createQuery($context);
$alias = $query->getRootAlias();
$query->where($expr->in('('.$alias.'.createdAt, '.$alias.'.group)', $subQuery));
}
Unfortunately it is not working and I'm not sure it's the right way to do it.
I could make it work with only selecting the createdAt in the in() expression but it's not what I want to have at the end.
Here is the error I got.
[Syntax Error] line 0, col 77: Error: Expected Doctrine\ORM\Query\Lexer::T_CLOSE_PARENTHESIS, got ','
How can I make it work using QueryBuilder ?
Thank you.