How to remove/hide the Add button after entering the employee's information?

For instance, after adding 1 occurrence of Demographic info details (My Client Groups > Personal Details) for an employee, is it possible to disable/hide the "Add" button to prevent users from adding additional demographic information?

Similarly in another scenario, if a user has already entered a payment method (My Client Groups > Show More > Personal Payment Method), can the "Add" button be disabled/hidden to prevent further entries?