from addons.sale.controllers.product_configurator import ProductConfiguratorController
from odoo import fields, http, tools
from odoo.http import request

class WebsiteSaleInherit(ProductConfiguratorController):
    @http.route(['/shop/change_pricelist/<model("product.pricelist"):pl_id>'], type='http', auth="public", website=True,
                sitemap=False)
    def pricelist_change(self, pl_id, **post):
        print('pl_id in super function', pl_id)
        if (pl_id.selectable or pl_id == request.env.user.partner_id.property_product_pricelist) \
                and request.website.is_pricelist_available(pl_id.id):
            request.session['website_sale_current_pl'] = pl_id.id
            request.website.sale_get_order(force_pricelist=pl_id.id)

        sample = request.env['product.pricelist.item'].sudo().search([])
        #I need to pass sample to XML file , I have used .qcontext but it doesnt worked
        return request.redirect(request.httprequest.referrer or '/shop')
XML file
​<odoo><data>
  <template id="products_stock_discount" inherit_id="website_sale.products_item"  name="Product discount">
    <xpath expr='//div[hasclass("oe_product_image")]' position='before'>               
           <t t-foreach="order" t-as="items">
                <div style="z-index: 20;" class="ribbon btn btn-danger oe_inline float-right">
                   <t t-esc="items.percent_price"/>% Offer
                </div>
            </t>
      </xpath>
   </template></data></odoo>