bp_is_large_install()

function bp_is_large_install() {
	// Use the Multisite function if available.
	if ( function_exists( 'wp_is_large_network' ) ) {
		$is_large = wp_is_large_network( 'users' );
	} else {
		$is_large = bp_core_get_total_member_count() > 10000;
	}

	/**
	 * Filters whether the current installation is "large".
	 *
	 * @since BuddyPress 4.1.0
	 *
	 * @param bool $is_large True if the network is "large".
	 */
	return (bool) apply_filters( 'bp_is_large_install', $is_large );
}