newsupernova/app/code/Magefan/Blog/Block/Adminhtml/Post/Edit/Tabs.php

<?php
/**
 * Copyright © 2015 Ihor Vansach (ihor@magefan.com). All rights reserved.
 * See LICENSE.txt for license details (http://opensource.org/licenses/osl-3.0.php).
 *
 * Glory to Ukraine! Glory to the heroes!
 */

namespace Magefan\Blog\Block\Adminhtml\Post\Edit;

/**
 * Admin page left menu
 */
class Tabs extends \Magento\Backend\Block\Widget\Tabs
{
    /**
     * @return void
     */
    protected function _construct()
    {
        parent::_construct();
        $this->setId('post_tabs');
        $this->setDestElementId('edit_form');
        $this->setTitle(__('Post Information'));
    }

    protected function _beforeToHtml()
    {
        $this->addTab(
            'related_posts_section',
            [
                'label' => __('Related Posts'),
                'url' => $this->getUrl('blog/post/relatedPosts', ['_current' => true]),
                'class' => 'ajax',
            ]
        );

        $this->addTab(
            'related_products_section',
            [
                'label' => __('Related Products'),
                'url' => $this->getUrl('blog/post/relatedProducts', ['_current' => true]),
                'class' => 'ajax',
            ]
        );
        return parent::_beforeToHtml();
    }
}