Add one more level for project timecard

Hi,

Per our understanding, project timecard will follow the project structure of a project built in Oracle Project Management module. Our client will have a 3 level project structure (Project > top task > subtask). However, in timecard perspective, our client wants to have 4 level to store the sub-team information (Project > top task > subtask> sub team). How can it be achieved in Oracle Time and Labor?

Thanks,

Alfred