Firstly, there may not be any bills for them to see in the Approval Tab, but this is most likely due to the User not being assigned to a Department.
If you have activated Internal Departments within Lightyear, you will need to complete the set up. The Department rules take effect immediately. This means ALL users can only view documents from Suppliers that are linked to the Departments that they are assigned to.
There are two scenarios this can occur:
If you have the setting activated and no Departments set up, users with Processing and/or Review and Export permissions will see everything but other User permission types will not be able to view/action any documents.
If you have set up a new User and they have not been assigned to any Department/s they will not see any bills.
Check that you have set up Departments correctly. To learn more about Departments, please see here.
Please Note: Users with Admin privilege can view all Departments.