Custom the_post_navigation at Wordpress from https://stackoverflow.com/questions/43999014/changing-a-next-previous-link-to-display-post-title

the_post_navigation.php

Use WordPress default function to get next and previous post title with permalink something like this:

    <?php  // FOR PREVIOUS POST
        $prev_post = get_previous_post(); 
        $id = $prev_post->ID ;
        $permalink = get_permalink( $id );
    ?>
    <?php // FOR NEXT POST
        $next_post = get_next_post();
        $nid = $next_post->ID ;
        $permalink = get_permalink($nid);
    ?>
    
Then just use this variable in your HTML structure like below:

<div class="next-timeline">
     <?php next_post_link( '%link', __( 'Next <span class="meta-nav">&rarr;</span>', 'twentyeleven' ) ); ?>
     <h2><a href="<?php echo $permalink; ?>"><?php echo $next_post->post_title; ?></a></h2>
</div>
<div class="previous-timeline">
     <?php previous_post_link( '%link', __( '<span class="meta-nav">&larr;</span> Previous', 'twentyeleven' ) ); ?> 
     <h2><a href="<?php echo $permalink; ?>"><?php echo $prev_post->post_title; ?></a></h2>                           
</div>

Thanks, great snippet.
Here is my slight alteration:

<?php
    $prev_post = get_previous_post();
    $prev_id = $prev_post->ID;
    $prev_permalink = get_permalink($prev_id);
    $next_post = get_next_post();
    $next_id = $next_post->ID;
    $next_permalink = get_permalink($next_id);
    ?>
    <aside class="container">
        <nav class="row">
            <div class="col-6 text-left">
                <div class="previous-timeline">
                    <a href="<?php echo $prev_permalink; ?>" rel="prev">
                        <span class="meta-nav">←</span> Previous
                        <h5><?php echo $prev_post->post_title; ?></h5>
                    </a>
                </div>
            </div>
            <div class="col-6 text-right">
                <div class="next-timeline">
                    <a href="<?php echo $next_permalink; ?>">
                        Next <span class="meta-nav">→</span>
                        <h5><?php echo $next_post->post_title; ?></h5>
                    </a>
                </div>
            </div>

        </nav>
    </aside>

Updated the variables for consistancy
Wrapped the Next and Title in a single

THANK YOU, GREAT CODE FOR ME