magento-test/app/code/Magento/Newsletter/Test/Mftf/ActionGroup/AdminCreateNewsletterTemplateActionGroup.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="AdminCreateNewsletterTemplateActionGroup" extends="AdminMarketingCreateNewsletterTemplateActionGroup">
        <annotations>
            <description>
                Extends AdminMarketingCreateNewsletterTemplateActionGroup.
                Clicks the Show/Hide button for the Template Content field before text is sent to this field.
            </description>
        </annotations>

        <waitForElementVisible selector="{{BasicFieldNewsletterSection.showHide}}" stepKey="waitForButton" before="showWYSIWYG"/>
        <conditionalClick selector="{{BasicFieldNewsletterSection.showHide}}" dependentSelector="{{TinyMCESection.ContentEditor}}" visible="false" stepKey="showWYSIWYG" before="waitForTemplateContentField"/>
    </actionGroup>
</actionGroups>