Get ACF field groups from parent.

acf-parent-fields.php

<?php 

add_filter('acf/settings/load_json', 'parent_theme_acf_load');

function parent_theme_acf_load($paths) {
  // Locate the parent template directory 
  $path = get_template_directory().'/acf-json';
  $paths[] = $path;
  
  return $paths;
}