Here’s an amazing list of Genealogy groups and pages on Facebook: https://socialmediagenealogy.com/genealogy-on-facebook-list/– it has a PDF (bit under 10.4 MB in size) you can download with the list. For more information, go to https://www.facebook.com/SocialMediaGenealogy.org. The website has links for a Canadian list and an Australian list:
Gail Dever has a broader Canadian list that includes French-speaking groups & pages, and that can be downloaded at Facebook for Canadian Genealogy. Alona Tester has an Australian list that can be downloaded at Facebook for Australian History & Genealogy.