There is an example on this page for queries based on sub fields for posts https://www.advancedcustomfields.com/resources/query-posts-custom-fields/ and the same principle could be applied to a user query https://codex.wordpress.org/Class_Reference/WP_User_Query.
I personally don’t like that option and find that it’s one of the repeater fields shortcomings. My personal preference is to create an acf/save_post filter that takes the content for the repeater and puts it into standard WP meta fields in the database so that I can search for them without all the extra overhead. An extremely simple example of this with a repeater would be…
add_action('acf/save_post', 'copy_repeater_to_standard')'
function copy_repeater_to_standard($post_id) {
if (substr($post_id, 0, 5) != 'user_') {
// not a user, bail
return;
}
$repeater = 'my_repeater'; // name of repeater field
$sub_field = 'my_sub_field'; // name of sub field
// the name of the new field. This is not an acf field
// just a custom user meta field
// that can be used for searching
$new_field = 'converted_sub_field';
$user_id = intval(substr($post_id, 5));
// first step is to delete any existing content from the new field
delete_user_meta($user_id, $new_field);
// now add content from the repeater
// an array to hold the values we've added
// because there is no point in saving them twice
$stored = array();
if (have_rows($repeater, $post_id)) {
while (have_rows($repeater, $post_id)) {
the_row();
$value = get_sub_field($sub_field, $post_id);
if ($value && !in_array($value, $stored)) {
$stored[] = $value;
// last parameter is false so that multiple values will be stored
add_post_meta($user_id, $new_field, $value, false);
}
}
}
}
in this case it is specific to a user, but could also be used for posts and terms by using the correct functions.
This took me only a few minutes to write and it may store a bit more in the db, but I’ve save myself a lot of trouble. Also, the queries on this new field will be much faster than the like queries that are needed to search a repeater sub field so it improves site performance.
