<?php
// Change "categories" to the name of your facet
add_filter( 'facetwp_facet_display_value', function( $label, $params ) {
if ( 'categories' == $params['facet']['name'] ) {
$term = get_term_by( 'id', $params['row']['term_id'] );
if ( ! empty( $term ) && ! empty( $term->description ) ) {
$label = esc_html( $term->description );
}
}
return $label;
}, 10, 2 );