magento-test/app/code/Magento/Cms/Test/Mftf/ActionGroup/StorefrontClickHeaderLinkActionGroup.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="StorefrontClickHeaderLinkActionGroup">
        <annotations>
            <description>Clicks a link in the storefront header.</description>
        </annotations>
        <arguments>
            <argument name="linkName" type="string" defaultValue="Create an Account"/>
        </arguments>

        <click stepKey="clickTheLink" selector="{{StorefrontHeaderSection.headerLinkByText(linkName)}}"/>
        <waitForPageLoad stepKey="wait"/>
    </actionGroup>
</actionGroups>