Updating custom fields across multiple tabs

@norbertk

I have made some changes to your code snippet.

/* 
 * Add field to account page 
 */

function um_account_custom_fields( $args ) {

	$args = str_replace( ',single_user_password', ',mobile_number,single_user_password', $args );
	return $args;
}
add_filter( 'um_account_tab_general_fields', 'um_account_custom_fields', 10, 1 );

/*
 * Add new tabs called "Notifications" and "Subscriptions"
 */

add_filter( 'um_account_page_default_tabs_hook', 'my_custom_tab_in_um', 100 );

function my_custom_tab_in_um( $tabs ) {

    $tabs[800]['notifications']['icon'] = 'um-faicon-envelope';
    $tabs[800]['notifications']['title'] = 'Notifications';
    $tabs[800]['notifications']['submit_title'] = 'Save';
    $tabs[800]['notifications']['custom'] = true;

    $tabs[800]['subscriptions']['icon'] = 'um-faicon-money';
    $tabs[800]['subscriptions']['title'] = 'Subscriptions';
    $tabs[800]['subscriptions']['show_button'] = false;
    $tabs[800]['subscriptions']['custom'] = true;

    return $tabs;
} 

 /* 
  * Add content to the Notifications tab
  */
 
add_filter( 'um_account_content_hook_notifications', 'um_account_content_hook_notifications', 10, 1 );

function um_account_content_hook_notifications( $output ) {

    $output .= '<div class="um-field">';

    // Meta keys for the UM fields to display
    $names = array( 'email_daily_digest_options', 
                    'um_block_6470_5', 
                    'email_deal_alert_options',
                );

    $fields = array(); 
    foreach( $names as $name ) {
        $fields[ $name ] = UM()->builtin()->get_specific_field( $name );
    }

    foreach( $fields as $key => $data ) {
        $output .= UM()->fields()->edit_field( $key, $data );
    }

    $output .= '</div>';

    return $output;
}

 /* 
 * Add content to the Subscriptions tab
 */

add_filter( 'um_account_content_hook_subscriptions', 'um_account_content_hook_subscriptions', 10, 1 );

function um_account_content_hook_subscriptions( $output ) {

    $output .= '<div>Subscriptions content</div>';

	return $output;
}
 
/* 
 * Ensure that the custom fields are updated when the account is updated 
 */

add_action( 'um_account_pre_update_profile', 'um_customtab_notifications_update', 100, 2 );

function um_customtab_notifications_update( $changes, $user_id ) {

    // meta keys to update
    $names = array( 'email_subscriptions', // Why ? not in the Tab
                    'email_daily_digest_options', 
                    'email_deal_alert_options' );

    foreach( $names as $name ) {
        if ( isset( $_POST[$name] )) {
            update_user_meta( $user_id, $name, sanitize_email( $_POST[$name] ));
        }
    }
}