Final answer:
To add the ability to assign tasks to groups outside of HR in the Lifecycle Events application, the customer should license the Human Resources Scoped App: Lifecycle Events.
Step-by-step explanation:
If the customer has already purchased HR Core and wants to add the Lifecycle Events application with the capability to assign tasks to groups outside of the HR organization, they should license the Human Resources Scoped App: Lifecycle Events. This specific application is designed to manage various HR events throughout the employee lifecycle and includes features that allow assigning tasks to different teams or groups, which may include those outside of the traditional HR organization.