FormBulder.php

<?php

$symfonyFormBuilder = $this->get('form.factory')
            ->createBuilder('form');

//An array of elements
$elements = array();

$symfonyFormBuilder->setAttribute('validation_constraint', new Callback(array("methods"=>array(
    'validate' => function ($data, $context) use ($elements) {
       // logic to add violations depending on the elements
        foreach($elements as $hash => $element) {
            $constraints = $element->getConstraints();
            foreach($constraints as $constraint) {
                $context->getGraphWalker()->walkConstraint($constraint, (isset($data[$hash]))?$data[$hash]:'', array(), 'children['.$hash.']');
            }
        }
    }
))));