Our thrift store implemented Workforce mobile app - the storage manager is able to approve time, do some scheduling, view shifts. But, mobile functionality is limited. 
I, an primary admin, was attempting to give the manager permissions to manage Time from desktop browser, but we are finding that there's no way to give custom role to the manager in QBO browser that would allow managing other employees time. The only option related to QB Time is the option to report own time. 
We even tried to work around by using the now-obsolete QuickBooks Time ( https://tsheets.intuit.com/), but it gives an error about lack of access to the company.
To summarize:

The user was given Time custom role and is able to access his own time at https://qbo.intuit.com/ 

The user (an admin in Quickbooks Time) is unable to access company at  ( https://tsheets.intuit.com/).

The user is able to manage others in Workforce app.