You will need to make a new site page (for more information on site page, please see this link).
When you get to your site pages Under Design > Site Pages, create a new page by clicking on the blue cross button.
When you create your site page, you need to enter the following information:
Title: This can be up to you, for our example, we'll use Advanced Search
SEO Name: This is very important and is part of the web link that comes to this advanced search page. You must enter products/advanced_search here.
The other fields are optional. If you would like the Advanced Search link to appear at the top, for the Tags section, add a tag called nav-main. If you would like the Advanced Search link to appear at the bottom, add a tag called nav-footer.
For more information, please get in touch with a support representative.