Create a select field or some other type of choice field. Dynamically generate the choices of this field from the options in the repeater field.
The document covers a select field but the same works with all choice type fields https://www.advancedcustomfields.com/resources/dynamically-populate-a-select-fields-choices/
The documentation still shows using acf/load_field but you should use acf/prepare_field instead https://www.advancedcustomfields.com/resources/acf-prepare_field/