magento-test/app/code/Magento/User/Test/Mftf/ActionGroup/AdminDeleteCustomUserActionGroup.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="AdminDeleteCustomUserActionGroup">
        <annotations>
            <description>Goes to the Admin Users grid page. Deletes the provided User. Validates that the Success Message is present and correct.</description>
        </annotations>
        <arguments>
            <argument name="user"/>
        </arguments>

        <amOnPage url="{{AdminUsersPage.url}}" stepKey="navigateToUserGrid"/>
        <fillField selector="{{AdminUserGridSection.usernameFilterTextField}}" userInput="{{user.username}}" stepKey="enterUserName"/>
        <click selector="{{AdminUserGridSection.searchButton}}" stepKey="clickSearch"/>
        <waitForPageLoad stepKey="waitForGridToLoad"/>
        <see selector="{{AdminUserGridSection.usernameInFirstRow}}" userInput="{{user.username}}" stepKey="seeUser"/>
        <click selector="{{AdminUserGridSection.searchResultFirstRow}}" stepKey="openUserEdit"/>
        <waitForPageLoad stepKey="waitForUserEditPageLoad"/>
        <fillField selector="{{AdminEditUserSection.currentPasswordField}}" userInput="{{_ENV.MAGENTO_ADMIN_PASSWORD}}" stepKey="enterThePassword"/>
        <click selector="{{AdminMainActionsSection.delete}}" stepKey="deleteUser"/>
        <waitForElementVisible selector="{{AdminConfirmationModalSection.message}}" stepKey="waitForConfirmModal"/>
        <click selector="{{AdminConfirmationModalSection.ok}}" stepKey="confirmDelete"/>
        <waitForPageLoad stepKey="waitForSave"/>
        <see selector="{{AdminMessagesSection.success}}" userInput="You deleted the user." stepKey="seeUserDeleteMessage"/>
    </actionGroup>
</actionGroups>