A Leave Type can be added in between the Leave Period in two ways,
(i) By creating a new leave type
(ii) Changing Entitlement to an existing leave type to an Employee.
By creating a new leave type While creating a new leave type, the system will show all the leave periods to which it needs to be added. If it has to be added in between an existing period, then the admin can add the entitlement accordingly on prorata basis.