HR can bulk add an end date to repeat payments as follows: Go to "HR Dashboard" > "Payroll" > click on "Pay Elements" > select the entity > click on "Repeat Payments/Deductions" > select the employees > click on "Bulk Actions" > "Change end date" > in the pop-up window select the end date and click on "Submit".
Note that HR cannot enter an end date to a repeat payment for themselves.