<?php

add_filter( 'facetwp_index_row', function( $params, $class ) {
    if ( in_array( $params['facet_name'], array( 'product_width', 'product_length' ) ) {
        $params['facet_value'] = $params['facet_display_value'];
    }
    return $params;
}, 10, 2 );