You can see both time and expense entries for any project status, including Completed, in the Time & Expense Reviewer (main menu > Time and Expenses). You can apply the relevant filters and period date range. The Time Entries screen is used for recording new time entries as well as reviewing entries; that is the reason we do not show completed project entries there in the Show by: Project mode.
You can also use the Time and Expense report that will show you all the time and expenses irrespective of the project status. Also, the Project Status filter is available there, which can be used to filter out different projects on the basis of their status.