You will need to enter absence on each employment, and can do one of the following:
Enter the paid leave on one employment and record it as unpaid leave on the other employments
Enter the leave or sickness based on how the hours or days are split on each employment
If you have any follow up questions as to how employees will be paid for sickness please direct these to your Payroll Agent. It will be up to Payroll how an employee is paid as this can't be managed on the HR software.