bp_get_taxonomy_term_site_id( string $taxonomy = '' )

function bp_get_taxonomy_term_site_id( $taxonomy = '' ) {
	$site_id = bp_get_root_blog_id();

	/**
	 * Filters the ID of the site where BP should store taxonomy terms.
	 *
	 * @since BuddyPress 2.6.0
	 *
	 * @param int    $site_id  Site ID to cehck for.
	 * @param string $taxonomy Taxonomy slug to check for.
	 */
	return (int) apply_filters( 'bp_get_taxonomy_term_site_id', $site_id, $taxonomy );
}