Using SelfEmployed, I have just about completed my return and want to review my business expenses (e.g. advertising, communications, etc) How do I find this page?

Type in the search box "Business Expenses" and click the "Jump to Business Expenses" link.  This will take you to business info screen.  Then click edit next to the business that you want to review and that will take you to the Business summary page and then you can scroll down to business expenses and click update. (see screenshots)