newsupernova/app/code/Mageplaza/Search/etc/adminhtml/system.xml

<?xml version="1.0"?>
<!--
/**
 * Mageplaza
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Mageplaza.com license that is
 * available through the world-wide-web at this URL:
 * https://www.mageplaza.com/LICENSE.txt
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade this extension to newer
 * version in the future.
 *
 * @category    Mageplaza
 * @package     Mageplaza_Search
 * @copyright   Copyright (c) 2017 Mageplaza (http://www.mageplaza.com/)
 * @license     https://www.mageplaza.com/LICENSE.txt
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
    <system>
        <section id="mpsearch" translate="label" sortOrder="130" showInDefault="1" showInWebsite="1" showInStore="1">
            <label>Search</label>
            <tab>mageplaza</tab>
            <resource>Mageplaza_Search::configuration</resource>
            <group id="general" translate="label" type="text" sortOrder="500" showInDefault="1" showInWebsite="1" showInStore="1">
                <label>General</label>
                <field id="enabled" translate="label comment" type="select" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label>Enable</label>
                    <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                </field>
                <field id="max_query_results" translate="label" type="text" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label>Maximum Number of Search Results</label>
                    <validate>validate-digits</validate>
                    <comment><![CDATA[By Default, it shows 10 search results]]></comment>
                </field>
                <field id="max_letter_numbers" translate="label" type="text" sortOrder="20" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label>Limit number of characters in description section</label>
                    <validate>validate-digits</validate>
                    <comment><![CDATA[Limit the length of short description.]]></comment>
                </field>
                <field id="display" translate="label" type="multiselect" sortOrder="40" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label>Information Display</label>
                    <source_model>Mageplaza\Search\Model\Config\Source\Display</source_model>
                </field>
                <field id="reindex_search" translate="label" type="select" sortOrder="50" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label>Reindex Search database</label>
                    <source_model>Mageplaza\Search\Model\Config\Source\Reindex</source_model>
                    <comment><![CDATA[<strong>After product save</strong> option is good choice for store has less than 3,000 products.
                   If your store has more than 3,000 SKUs, you should switch to Cron job, it runs daily at 0AM your server time.]]></comment>
                </field>
                <field id="btn_reindex" translate="button_label" sortOrder="55" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label></label>
                    <button_label>Reindex Search Data</button_label>
                    <button_url>mpsearch/search/generate</button_url>
                    <frontend_model>Mageplaza\Search\Block\Adminhtml\System\Config\Button</frontend_model>
                </field>
                <group id="category" translate="label" showInDefault="1" sortOrder="100" showInWebsite="1" showInStore="1">
                    <label>Search by category configuration</label>
                    <field id="enable" translate="label" type="select" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1">
                        <label>Enable Search By Category</label>
                        <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                    </field>
                    <field id="max_depth" translate="label" type="text" sortOrder="20" showInDefault="1" showInWebsite="1" showInStore="1">
                        <label>Maximal Depth</label>
                        <depends>
                            <field id="enable">1</field>
                        </depends>
                    </field>
                </group>
            </group>
        </section>
    </system>
</config>