magento-test/app/code/Magento/Customer/Test/Mftf/ActionGroup/EnterCustomerAddressInfoFillStateActionGroup.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="EnterCustomerAddressInfoFillStateActionGroup" extends="EnterCustomerAddressInfoActionGroup">
        <annotations>
            <description>EXTENDS: EnterCustomerAddressInfoActionGroup. Fills the State field.</description>
        </annotations>

        <fillField stepKey="selectState" selector="{{StorefrontCustomerAddressSection.stateProvinceFill}}" userInput="{{Address.state}}"/>
    </actionGroup>
</actionGroups>