title: Get field value of sub site in wordpress by ACF
body: <p>We have a <code>Wordpress</code> website which has 10 sub sites(blogs) . We show the latest post of those sub sites on the main site . Recently we added and use <a href="https://www.advancedcustomfields.com/" rel="nofollow">Advanced Custom Field</a> which is active now on the main site and all those 10 sub sites and in each one we sat just a true/false  field and its name is  : <code>is_announce</code> . 
  In each site ( main or sub sites ) we have access to that field by <code>get_field</code> and it works great .
  The problem is , on the main site we have no access to those fields of sub sites.It seems <code>get_field</code> works good just for each site's scope ( main or sub sites )</p>
  
  <p>How can we fix it ?</p>
  
  <p>Addition : As i told you we show the latest post of each sub website . each one has been featured by one custom field (<code>is_announce</code>) . We want to read its value and if it is <code>True</code> , show something on the top of each post , something like tag .</p>