class Spider(scrapy.Spider):
    name = 'scrapyspider'
    allowed_domains = ['www.example.com']
    start_urls = ['https://www.example.com/1/', 'https://www.example.com/2/']


    def parse(self, response):
        for product_link in response.xpath(
                '//a[@class="product-link"]/@href').extract():
            absolute_url = response.urljoin(product_link)
            yield scrapy.Request(absolute_url, self.parse_product)
        for category_link in response.xpath(
            '//a[@class="navigation-item-link"]/@href').extract():
            absolute_url = response.urljoin(category_link)
            yield scrapy.Request(absolute_url, self.parse)

    def parse_product(self, response):
        ...
        yield item