/**
* Only include direct children in category facets
*
*/
add_filter( 'facetwp_index_row', function( $params, $class ) {
if ( 'tax/category' == $params['facet_source'] ) {
if ( 0 !== $params['depth'] ) {
$params['facet_value'] = ''; // don't index this row
}
}
return $params;
}, 10, 2 );