Create a new file nextpreviouspagination.phtml at app/design/frontend/Vendor/theme/Magento_Catalog/templates/product/view/.
Add following code in this new file:

<?php 

    $productId = $block->getProduct()->getId(); 
    $categoryIds = $block->getProduct()->getCategoryIds();

    $objectManager = MagentoFrameworkAppObjectManager::getInstance();

    $nxtProduct = $objectManager->create('MagentoCatalogModelProduct');
    $prvProduct = $objectManager->create('MagentoCatalogModelProduct');

    $category = $objectManager->create('MagentoCatalogModelCategory')->load($categoryIds[0]);
    $categoryProduct = $category->getProductCollection()->addAttributeToSort('position', 'asc');
    $categoryProduct->addAttributeToFilter('status',1);
    $categoryProduct->addAttributeToFilter('visibility',4);

    $categoryProductIds = $categoryProduct->getAllIds();

    $position = array_search($productId, $categoryProductIds); // get position of the current product
    $nextPosition = $position+1;
    $previousPosition = $position-1;
    $keys = array_keys($categoryProductIds);

    if(in_array($nextPosition, $keys)){
        $nextProduct = $nxtProduct->load($categoryProductIds[$nextPosition]);
    }
    if(in_array($previousPosition, $keys)){
        $previousProduct = $prvProduct->load($categoryProductIds[$previousPosition]);   
    }

?>

<div class="previous_next">
    <?php if(in_array($previousPosition, $keys)): ?>
        <a href="<?php print_r($previousProduct->getProductUrl()); ?>"><span>Previous </span></a>
    <?php endif; ?>

    <?php if(in_array($nextPosition, $keys)): ?>
        <a href="<?php print_r($nextProduct->getProductUrl()); ?>"><span>Next </span></a>
    <?php endif; ?>
</div>

Now open this file app/design/frontend/Vendor/theme/Magento_Catalog/layout/catalog_product_view.xml.
Add following code between body tag of the catalog_product_view.xml file:

<referenceContainer name="content">
    <block class="MagentoCatalogBlockProductViewDescription" name="product.info.nextpreviouspagination" template="product/view/nextpreviouspagination.phtml" />   
</referenceContainer>

<move element="product.info.nextpreviouspagination" destination="product.info.main" after="page.main.title"/>