I do not see any way to do this in the SCL manual, how does batch package approval identify which group it is approving for >
After the Approver groups are built one relates the Approver group to an Endevor inventory area ( environment, system,type, etc). Then, when a package is cast it will review all the action's inventory area to see if an approver group has been related to that area. If one has been related that Approver Group will become associate to the package as part of the cast action. This is done automatically via the cast action.
For more information please see the Endevor Package Guide section on Determining Package Approvers.
I am familiar with how the approver groups work, my question was if there was any way to specify which approver group a batch approval was approving for. (generated from 'approve package SCL'.
From you answer it appears the userid that the batch process executes under is the key, if that user is found in an approver group, the package is approved for that approver group.