이 답변은 Marius에서 제공합니다 ♦ 카테고리 탭 메뉴에 하위 카테고리를 추가하도록 Marius ♦의 답변을 참조 할 수 있도록 방금 수정했습니다. 방금 메인 카테고리에 하위 카테고리를 추가하도록 하위 Topmenu.php 파일을 수정했습니다.

<?php

namespace Ktpl\Navigationlink\Plugin\Block;

use Magento\Framework\UrlInterface;
use Magento\Framework\Data\Tree\NodeFactory;
use Magento\Store\Model\StoreManagerInterface;

class Topmenu
{
    /**
     * @var NodeFactory
     */
    protected $nodeFactory;
    protected $urlBuilder;
    protected $_storeManager;

    public function __construct(
        UrlInterface $urlBuilder,
        NodeFactory $nodeFactory,
        StoreManagerInterface $storeManager
    ) {
        $this->urlBuilder = $urlBuilder;
        $this->nodeFactory = $nodeFactory;
        $this->_storeManager = $storeManager;
    }

    public function beforeGetHtml(
        \Magento\Theme\Block\Html\Topmenu $subject,
        $outermostClass = '',
        $childrenWrapClass = '',
        $limit = 0
    ) {
        // condition for store
        if($this->getStoreCode() == 'store_id'):
        $productNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Products','products'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $stockistsNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Stockists','stockists'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $ourstoryNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Our Story','ourstory'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $contactsNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Customer Care','contacts'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        /******* contacts's child *******/
        $warrantyRegistrationNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Warranty Registration','warranty-registration'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $faqNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Frequently Asked Questions','faq'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $ourProductGuaranteeNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Our Product Guarantee','our-product-guarantee'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $warrantiesNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Warranties, Repairs & Spare Parts','warranties-repairs-spare-parts'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $termsNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Terms & Conditions','terms-and-conditions'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $privacyPolicyNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Our Privacy Policy','privacy-policy'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );
        $bookNode = $this->nodeFactory->create(
            [
                'data' => $this->getNodeAsArray('Book A Viewing','book-a-viewing'),
                'idField' => 'id',
                'tree' => $subject->getMenu()->getTree()
            ]
        );

        $contactsNode->addChild($warrantyRegistrationNode);
        $contactsNode->addChild($faqNode);
        $contactsNode->addChild($ourProductGuaranteeNode);
        $contactsNode->addChild($warrantiesNode);
        $contactsNode->addChild($termsNode);
        $contactsNode->addChild($privacyPolicyNode);
        $contactsNode->addChild($bookNode);
        /******* end contacts's child *******/

        $subject->getMenu()->addChild($productNode);
        $subject->getMenu()->addChild($stockistsNode);
        $subject->getMenu()->addChild($ourstoryNode);
        $subject->getMenu()->addChild($contactsNode);
        endif;
    }

    protected function getNodeAsArray($name,$id)
    {
        return [
            'name' => __($name),
            'id' => $id,
            'url' => $this->urlBuilder->getUrl($id),
            'has_active' => false,
            'is_active' => false // (expression to determine if menu item is selected or not)
        ];
    }

    public function getStoreCode()
    {
        return $this->_storeManager->getStore()->getCode();
    }
}

상위 카테고리 및 하위 카테고리에 대한 노드를 작성해야하며 그 후 addChild 메소드를 사용하여 상위 카테고리에 하위 카테고리를 지정할 수 있습니다. 여기 예가 있습니다.

$contactsNode->addChild($warrantyRegistrationNode);

답변

<?php
namespace Seatup\Navigation\Observer;
use Magento\Framework\Event\Observer as EventObserver;
use Magento\Framework\Data\Tree\Node;
use Magento\Framework\Event\ObserverInterface;
class Topmenu implements ObserverInterface
{
    protected $_cmsBlock;

    public function __construct(
        \Magento\Cms\Block\Block $cmsBlock
    )
    {
        $this->_cmsBlock = $cmsBlock;
    }
    /**
     * @param EventObserver $observer
     * @return $this
     */
    public function execute(EventObserver $observer)
    {
        /** @var \Magento\Framework\Data\Tree\Node $menu */
        $eventName = $observer->getEvent()->getName();
        if($eventName == 'page_block_html_topmenu_gethtml_before'){
            // With the event name you can edit the tree here
            $menu = $observer->getMenu();
            $tree = $menu->getTree();
            $children = $menu->getChildren();

            foreach ($children as $child) {
                if($child->getChildren()->count() > 0){ //Only add menu items if it already has a dropdown (this could be removed)
                    $childTree = $child->getTree();
                    $data1 = [
                        'name'      => __('Menu item label here'),
                        'id'        => 'some-unique-id-here',
                        'url'       => 'url goes here',
                        'is_active' => FALSE
                    ];
                    $node1 = new Node($data1, 'id', $childTree, $child);
                    $childTree->addNode($node1, $child);
                }
            }
            return $this;
        } else if($eventName == 'page_block_html_topmenu_gethtml_after'){
            // With the event name you can edit the HTML output here
            $transport = $observer['transportObject'];

            //get the HTML
            $old_html = $transport->getHtml();

            //render the block. I am using a CMS block
            $new_output = $this->_cmsBlock->getLayout()->createBlock('Magento\Cms\Block\Block')->setBlockId('cms_block_identifier')->toHtml();
            //the transport now contains html for the group/class block
            //which doesn't matter, because we already extracted the HTML into a 
            //string primitive variable
            $new_html = str_replace('to find', $new_output , $old_html);
            $transport->setHtml($new_html);
        }
    }
}

app/design/frontend/Vendor/theme/Magento_Theme/layout/default.xml

<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
    <body>
        <referenceContainer name="catalog.topnav">
           <block class="Magento\Framework\View\Element\Html\Link\Current" name="gallery.link">
                <arguments>
                    <argument name="label" xsi:type="string">Gallery</argument>
                    <argument name="path" xsi:type="string">gallery</argument>
                </arguments>
          </block>
       </referenceContainer>
    </body>
</page>

Title = Gallery
Url Key = gallery
Link = https://example.com/gallery/

.navigation .nav.item {
margin: 0 10px 0 0;
display: inline-block;
position: relative;
}