Category::getItemsFilter

public function getItemsFilter(array $filter = []): array
{
	if($this->getIsDefault())
	{
		$filter[] = [
			'LOGIC' => 'OR',
			[
				'=CATEGORY_ID' => 0,
			],
			[
				'=CATEGORY_ID' => null,
			],
			[
				'=CATEGORY_ID' => $this->getId(),
			],
		];
	}
	else
	{
		$filter['=CATEGORY_ID'] = $this->getId();
	}

	return $filter;
}