magento-test/app/code/Magento/Cms/Test/Mftf/ActionGroup/AdminExpandContentSectionActionGroup.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-->

<actionGroups xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:noNamespaceSchemaLocation="urn:magento:mftf:Test/etc/actionGroupSchema.xsd">
    <actionGroup name="AdminExpandContentSectionActionGroup">
        <annotations>
            <description>Expand Content section on the Admin CMS Page creation/edit.</description>
        </annotations>
        <click selector="{{CmsNewPagePageContentSection.header}}" stepKey="expandContentSection"/>
        <waitForPageLoad stepKey="waitForContentSection"/>
    </actionGroup>
</actionGroups>