#!/bin/sh
burl=https://rskrf.ru/rest/1/catalog/categories/
curl -s $burl | jq -cr '.response[]|.id' |
  xargs -I '{}' curl -s $burl'{}' |
  jq -cr '.response[]|.id' |
  xargs -I '{}' curl -s $burl'{}'/productGroups/ |
  jq -cr '.response.productGroups[]|[.id,.title]'