How to build sub-pages?

[apollonian]

Here I have a question:

I build a page for one type of product, for example, its URL will be "mysite.com/product1" after I publish the site.

On this page, there are lots of products, for example, from item #1 to #10. Then I build 10 pages for each of them. How can I make the URL, after publish, shows as "mysite.com/product1/item#"?

But after I build so many pages, each item has a URL of "mysite.com/item#".

I upload a picture to explain more clearly.



Any suggestion is appreciated.