collection-crud/src/Form/BrandCategoryTrait.php

<?php declare(strict_types=1);

namespace App\Form;

use Doctrine\ORM\{EntityRepository, QueryBuilder};

trait BrandCategoryTrait {
	public static function filterBrands(string $filter): callable
	{
		return static fn (EntityRepository $e) => $e->createQueryBuilder('b')
			->join('b.categories', 'bc')
			->where('bc.name=:name')
			->orderBy('b.name', 'ASC')
			->setParameter('name', $filter);
	}
}