Hi @robbiegod,
Thanks for the post.
I would recommend you hook into the acf/load_field filter and use this to pass the selected field object from the other relationship field on the other page.
The code would look like so:
<?php
function my_acf_load_field( $field ) {
//get the field object
$field['value'] = $new_field_value
return $field;
}
// key
add_filter('acf/load_field/key=field_508a263b40457', 'my_acf_load_field');
?>
