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You can use wp_get_post_parent_id to return just the parent ID of the page in question. Then you can use get_the_title and get_permalink with that parent ID to build a back button to the parent page;

<?php if( $parent = wp_get_post_parent_id( get_the_ID() ) ): ?>
<a href="https://wordpress.stackexchange.com/questions/167269/<?php echo get_permalink($parent); ?>"><?php echo get_the_title($parent); ?></a>
<?php endif; ?>

Something like this should work. Unable to test this but it should be fine.

Alternatively you could get the entire post parent with get_post and bring out the data you need that way but that is probably more CPU intensive for such a simple thing as getting a link.