This feature is available in Enterprise and Ultimate editions.
The Timesheet Audit report shows the timesheet submission history by team member and week.
Accessing this Report
To view this report, you Admin Privileges role must be set to "Member Admin" or higher.
On the main menu:
Reports > Timesheet Audit (in the Member/Team Reports section)
My Home > Timesheets > Timesheet Audit Report button
This feature was added in the Winter 2017 (17.0) release. It is not available in older versions of Lifecycle.