Magento2 Module Development – Add Module Block Inside Another Module’s PHTML File

you can keep below code,

Keep inside Static block below code,

{{block class="Magento\Catalog\Block\Navigation" templates="catalog/navigation/categoryblocks.phtml"}}

Below file keep inside your app/design/frontend/Vendorname/themename/Magento_Catalog/templates/catalog/navigation/categoryblocks.phtml

    <?php 
            //If there are sub categories
            $categories = $block->getCurrentChildCategories();
            $categoriescount = $block->getCurrentChildCategories()->count();
            if ($categoriescount > 0):  ?>
            <div class="container_12">  
            <?php 
                //Loop through categories
                foreach ($categories as $category): ?>
                <div class="grid_3 alpha special-spacing" style="margin-bottom:10px;">
                    <div>
                        <!--<p class="cat-link"><?php echo $category->getName()?></p>-->
                        <a href="<?php echo $block->getCategoryUrl($category) ?>" class="cat-link"><?php echo $category->getName()?></a>
                    </div>
                    <?php //get category products
                    $categoryProducts = $category->getProductCollection();
                       if(count($categoryProducts) <> 1):?>
                    <a href="<?php echo $block->getCategoryUrl($category)?>" class="cat-image">
                    <?php else:?>
                    <?php $product = $categoryProducts->getFirstItem();?>
                    <a href="<?php echo $product->getProductUrl()?>" class="cat-image">
                    <?php endif;?>
                    </a>
                </div>

                <?php endforeach; ?>
            <div class="clear"></div>
            </div>
            <?php else:?>
    <h3>product not 

found...</h3>
<?php endif;?>

You can call any template file inside any template file using below line

<?php echo $this->getLayout()->createBlock('Magento\Framework\View\Element\Template')->setTemplate('Company_Module::test.phtml')->toHtml(); ?>