magento-test/app/code/Magento/Checkout/Test/Mftf/ActionGroup/LoggedInCheckoutFillNewBillingAddressActionGroup.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="LoggedInCheckoutFillNewBillingAddressActionGroup">
        <annotations>
            <description>Fills in the provided Address details on the Storefront Checkout Address sections based on the provided Class Prefix (i.e. '._show', '[aria-hidden=false]').</description>
        </annotations>
        <arguments>
            <argument name="Address"/>
            <!-- the classPrefix argument is to specifically select the inputs of the correct form
                 this is to prevent having 3 action groups doing essentially the same thing -->
            <argument name="classPrefix" type="string" defaultValue=""/>
        </arguments>

        <fillField stepKey="fillFirstName" selector="{{classPrefix}} {{CheckoutShippingSection.firstName}}" userInput="{{Address.firstname}}"/>
        <fillField stepKey="fillLastName" selector="{{classPrefix}} {{CheckoutShippingSection.lastName}}" userInput="{{Address.lastname}}"/>
        <fillField stepKey="fillCompany" selector="{{classPrefix}} {{CheckoutShippingSection.company}}" userInput="{{Address.company}}"/>
        <fillField stepKey="fillPhoneNumber" selector="{{classPrefix}} {{CheckoutShippingSection.telephone}}" userInput="{{Address.telephone}}"/>
        <fillField stepKey="fillStreetAddress1" selector="{{classPrefix}} {{CheckoutShippingSection.street}}" userInput="{{Address.street[0]}}"/>
        <fillField stepKey="fillStreetAddress2" selector="{{classPrefix}} {{CheckoutShippingSection.street2}}" userInput="{{Address.street[1]}}"/>
        <fillField stepKey="fillCityName" selector="{{classPrefix}} {{CheckoutShippingSection.city}}" userInput="{{Address.city}}"/>
        <selectOption stepKey="selectState" selector="{{classPrefix}} {{CheckoutShippingSection.region}}" userInput="{{Address.state}}"/>
        <fillField stepKey="fillZip" selector="{{classPrefix}} {{CheckoutShippingSection.postcode}}" userInput="{{Address.postcode}}"/>
        <selectOption stepKey="selectCounty" selector="{{classPrefix}} {{CheckoutShippingSection.country}}" userInput="{{Address.country_id}}"/>
        <waitForPageLoad stepKey="waitForFormUpdate2"/>
    </actionGroup>
</actionGroups>