In Classic UI there is the ability to see Timesheets for Expense Type resources as long as they are Open for Time Entry and have Track Mode = PPM.
How can I see timesheets for Expense Resources in the New UX?
New UX for versions 15.1 through 15.4 at this time.
Only labor resources are available in the New UX at this time.
Therefore you cannot see timesheets or any other Staffing information for Expense Resources.