There are 2 ways to do this, and I don’t have all the details on doing either.
The first would require the page to be saved after entering the repeater values. You could then use an acf/load_field filter https://www.advancedcustomfields.com/resources/acfload_field/ to load the values of the checkbox field, although I’m not sure how you’d make sure you were getting the values from the same layout, or even if this is possible since each layout would have it’s own set of choices and I think that this will make all the choices the same for all layouts.
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