I haven’t found a solution for this but I found another solution that fit my problem, with this code is possible to pre-populate nested fields with some default value:
add_filter('acf/load_value/key=field_607879a1215fc', 'acf_load_default', 10, 3);
function acf_load_default($value, $post_id, $field)
{
if ($value === false) {
$value = array();
$value[] = array(
'field_6081eeaf5a418' => 'Example Title One',
);
$value[] = array(
'field_6081eeaf5a418' => 'Example Title Two',
'field_6081eeb75a419' => array(
array('field_6081eebf5a41a' => 'Example Title Three'),
array('field_6081eebf5a41a' => 'Example Title Four')
)
);
}
return $value;
}
any suggestion on how to fix this?