Members with the Administrator role can always approve anyone’s entries.
However, there are two different options for setting up which time logs will go to which Manager for approval:
If you wish for the Managers of different teams to only approve entries for the Normal users of their own team, you need to create Teams and assign members to them. For the Manager, additionally, select these two options on their profile:
For the Managers to be able to approve entries of all members that work on the same projects as them, just select ‘Can approve and reject time logs’ when setting up their role. In this case, Managers will be able to approve all time logs that were entered on the projects assigned to them.