// Include Field
<?php the_field('projectPage_sub_title'); ?>
// Check if field exist
<?php if (get_field('projectPage_gallery')): ?>
// ACF Repeater loop
<?php while ( have_rows('repeater_') ) : the_row(); ?>
// Include sub field
<?php the_sub_field('projectPage_gallery_item'); ?>
<?php endwhile; ?>
<?php endif; ?>