You can check the products that are returned by an upsell or cross-sell rule in your demo shop. Search for the product that you want to check and click it. You will see a popup that shows you details on the product. When you click the Recommendations tab, it will show all upsell and cross-sell rules that were applied to this product. Click the dropdown to see which items will be shown as up and cross sell items.
If you want to see the outcome in XML or JSON format, you can click the Recommendations source data option:
Note: you need to succesfully run a publish task before any changes are visible in the demo shop.