I found the solution, i post it here if it can help someone :
<?php if( have_rows('evenement') ): ?>
<div class="map">
<div class="acf-map">
<?php while ( have_rows('evenement') ) : the_row(); ?>
<?php $post_object = get_sub_field('lieu_evenement');if( $post_object ): ?>
<?php $post = $post_object; setup_postdata( $post ); ?>
<?php $location = get_field('geolocalisation'); if( !empty($location) ):?>
<div class="marker" data-lat="<?php echo $location['lat']; ?>" data-lng="<?php echo $location['lng']; ?>">
<div class="lieu"><?php the_title(); ?></div>
</div>
<?php endif; ?>
<?php wp_reset_postdata(); ?>
<?php endif; ?>
<?php endwhile; ?>
</div>
</div>
<?php else: ?>
<?php endif; ?>
