How to inherit field value from parent post into in child / sub post

You can use get_post_field( 'post_parent' ) to get the parent ID of the current post.

Whilst ACF is technically off-topic, FWIW you can pass the ID of a post as the second parameter to get_field.

Combined together we can fashion a shortcode centre_field that will return any field value for the post’s parent. I’ve skipped the need for an attribute name as I think the shortcode looks a little cleaner…

e.g. [centre_field phone_number]

And the code behind it:

function wpse_405660_centre_field( $atts ) {
    // Just grab the first value of the attribute array
    $field_name = current( $atts );

    $parent_id = get_post_field( 'post_parent' );

    return get_field( $field_name, $parent_id );
}

add_shortcode( 'centre_field', 'wpse_405660_centre_field' );