Hi there,
Could you please try something like this :
<?php
$group = get_field('group_field');
$heading = $group['heading'];
$text = $group['text'];
$repeater = $group['links_list']; //
?>
<h3><?php echo $heading; ?></h3>
<?php echo $text; ?>
<?php if( have_rows($repeater) ) : ?>
<ul class="links-list">
<?php while( have_rows($repeater) ) : the_row(); $link = get_sub_field('link'); ?>
<li><a href="<?php echo $link['url']; ?>" target="<?php echo $link['target']; ?>"><?php echo $link['title']; ?></a></li>
<?php endwhile; ?>
</ul>
<?php endif;?>
Explanation
As a repeater field, the group field is a row of datas, but it contains a single row.
(as it’s explained in the documentation: https://www.advancedcustomfields.com/resources/group/)
In your code, you tried to have the repeater fields datas, without indicating in which $row your repeater field is (your group field).
Let me know if it helps.
