yii\mongodb\QueryBuilder::buildOrCondition PHP Method

    public function buildOrCondition($operator, $operands)
    {
        $operator = $this->normalizeConditionKeyword($operator);
        $parts = [];
        foreach ($operands as $operand) {
            $parts[] = $this->buildCondition($operand);
        }
        return [$operator => $parts];
    }