1. Log in to your verified Facebook account.
3. Group ID you can get using search by group name. Go to group page and copy group name from link in address bar
4. Under the Graph API enter “search?type=group&q=” and paste Group Name, then click on submit, all the groups that match search criteria will appear. Copy ID from first group (underlined).
5. Under the Graph API paste Group ID and put /members at the end. Click on submit and you will get JSON with groups members.
5.2. or make direct link using got your access token and the group id : https://graph.facebook.com/v2.5/GroupIDHere/members?limit=500&access_token=YourAccessTokenHere
and go to Convert JSON as external resource and paste JSON in External JSON Resource: field on Url tab.
6. Choose conversion options, enter reCAPTCHA and click Submit.