Sync the roles associated with each of the user's member types on each subsite of a multisite network

sync_member_type_roles.php

/**
 * Retrieves an array of all network sites
 *
 * @since 1.0
 * @return array
 */
function get_network_sites() {
	global $wpdb;

	$blogs = $wpdb->get_results("
		SELECT blog_id
		FROM {$wpdb->blogs}
		WHERE site_id = '{$wpdb->siteid}'
		AND spam = '0'
		AND deleted = '0'
		AND archived = '0'
	");

	$sites = array();
	$sites[0] = __( 'None', 'onesocial' );

	foreach ( $blogs as $blog ) {
		$sites[ $blog->blog_id ] = get_blog_option( $blog->blog_id, 'blogname' );
	}

	natsort( $sites );
	unset( $sites[0] );

	return apply_filters( 'network_sites', $sites );
}	


if ( class_exists( 'BuddyPress' ) ) {

	/**
	 * Update role for all other subsites on member type change
	 *
	 * @param int     $user_id numeric user id.
	 * @param string  $member_type new member type.
	 * @param boolean $append whether the member type was appended or reset.
	 */
	function bp_ms_update_roles( $user_id, $member_type, $append ) {
		
		if ( ! function_exists( 'bpmtp_get_member_type_associated_roles' ) ) return;
		
		$sites = get_network_sites();
		$original_site = get_current_blog_id();

		foreach( $sites as $blog_id => $site_name ) { 

			// Skip updating roles on the original site
			if ( $blog_id == $original_site )
				continue;

			switch_to_blog( $blog_id );

			$roles = bpmtp_get_member_type_associated_roles( $member_type );
			// We do not modify roles if the user is super admin or the new roles list is empty.
			// Based on feedbak, we may want to remove all roles for empty in future.
			if ( empty( $roles ) || is_super_admin( $user_id ) ) {
				return;
			}

			$user = get_user_by( 'id', $user_id );

			if ( ! $user ) {
				return;
			}

			// remove all roles.
			$user->set_role( '' );

			// Now add the one/more roles to the user.
			foreach ( $roles as $role ) {
				$user->add_role( $role );
			}

			restore_current_blog();
		}	

	}
	add_action( 'bp_set_member_type', 'bp_ms_update_roles', 10, 3 );

}