Sonata Admin Bundle> configureListFields>如何引用列查询的字段值？

Within configureListFields, I want to perform an additional query and get data related to the current row, but I don't know how to access a reference value to do so.

Here's what I have currently, but what I'm currently using to access the value doesn't work:

protected function configureListFields(ListMapper $listMapper)
{
    $historicalCommissions = $this
        ->getConfigurationPool()
        ->getContainer()
        ->get('doctrine')
        ->getRepository('MyBundle:MyEntity')
        ->findBy(['card_id' => $listMapper->get('card_id')]);

    $listMapper
        ->addIdentifier('id')
        ->add('field')
        ->add('field')
        ->add('historical_commissions', ...);
}

The first thought is to modify the parent query in createQuery(), however, what I'm looking for is a list of multiple values in the additional query, and doctrine doesn't have any implementation of anything like mysql's GROUP_CONCAT (that I am aware of).

Suggestions?