I don’t have a concrete example of the second method, basically because I would never to it that way. It far too complicated and too much work to achieve.
I would use the first method and create an acf/save_post action. In this action I would loop through the repeater and create another custom post meta field that is a concatenation of the two fields I want to search. I would then do my WP_Query based on this new field that is stored in standard WP fashion. I know that this seems like it’s coming at the problem backwards, but it’s really the easiest way.
