New Annual Vacation rules

Hi Gurus,

We are working on 12.0.6 versions This is a requirement from Oracle Absence management.I need your quick suggestion on how to proceed with this requirement.

Currently the remaining leaves at the end of every year are adding into Carry over element and showing the old leave balance.

Client want the below change from now,

1) There should be a separate container to store old leave balance and the new leave balance(new leave balance is current year Accrual balance)

2) There should be a control on self service page to select for user whether they are utilizing the leave from from Old leave balance or from New leave balance.(Can this be done on absence request page?)