Magento 2: create new page layout for specific cms page

If you want to set different blocks, content, or design for a specific page, then you can do that like below.

First you need to create new file under your theme Magento_Cmslayoutcms_page_view_id_{{identifier of page}}.xml

then you can move and add your block which you want like below.

<?xml version="1.0"?>
<!--
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
-->
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<head>
<script async="async" src="Magento_Cms::js/custom.js"/>
</head>
</page>

Note: Here I have added custom js only for a specific page like cms_page_view_id_about-us.xml