Hide User List in WordPress Admin Panel with Code

Code

<?php
// Hook into the 'pre_user_query' to modify the user query
add_action('pre_user_query', 'wp_dudecom_hide_admin_user_from_list');

/**
 * Hide a specific admin user from the user list in the WordPress admin panel.
 *
 * @param WP_User_Query $user_search The current WP_User_Query instance.
 */
function wp_dudecom_hide_admin_user_from_list($user_search) {
    // Check if the current user has the capability to edit users
    if (current_user_can('edit_users')) {
        global $wpdb;

        // Specify the username of the admin you want to hide
        $hidden_username = 'hidden_admin_username';

        // Modify the query to exclude the specified user
        $user_search->query_where .= $wpdb->prepare(" AND {$wpdb->users}.user_login != %s", $hidden_username);
    }
}

// Hook into 'editable_roles' to remove the Administrator role from the dropdown
add_filter('editable_roles', 'wp_dudecom_remove_admin_role_from_dropdown');

/**
 * Remove the Administrator role from the role dropdown in the WordPress admin panel.
 *
 * @param array $roles The array of roles.
 * @return array Modified array of roles.
 */
function wp_dudecom_remove_admin_role_from_dropdown($roles) {
    // Check if the current user has the capability to edit users
    if (current_user_can('edit_users')) {
        // Remove the Administrator role from the roles array
        unset($roles['administrator']);
    }
    return $roles;
}

// Hook into 'user_has_cap' to prevent editing of the hidden admin user
add_filter('user_has_cap', 'wp_dudecom_prevent_edit_hidden_admin', 10, 4);

/**
 * Prevent editing of the hidden admin user by other users.
 *
 * @param array $allcaps All the capabilities of the user.
 * @param array $caps Required capabilities.
 * @param array $args Arguments passed to the capability check.
 * @param WP_User $user The current user object.
 * @return array Modified capabilities.
 */
function wp_dudecom_prevent_edit_hidden_admin($allcaps, $caps, $args, $user) {
    // Specify the username of the admin you want to hide
    $hidden_username = 'hidden_admin_username';

    // Check if the current user is trying to edit the hidden admin user
    if (isset($args[2]) && $args[2] === $hidden_username) {
        // Remove the capability to edit the hidden admin user
        $allcaps['edit_user'] = false;
        $allcaps['delete_user'] = false;
        $allcaps['promote_user'] = false;
    }
    return $allcaps;
}
?>