<?php
// To exclude custom fields from FacetWP's get_data_sources() function, used in the admin area, you can use
// the 'facetwp_excluded_custom_fields' filter.
// To do it by partial match, e.g. for fields with a hashed part of the name,
// you can use the 'facetwp_excluded_custom_fields_like' filter,
// available in FacetWP 4.5+ :
add_filter( 'facetwp_excluded_custom_fields_like', function( $not_like ) {
$not_like[] = '_crp_cache_'; // exclude cache rows added by Contextual Related Posts plugin
return $not_like;
});