In the previous graph api version 2.7 this was working for all count (total, like, comment):
https://graph.facebook.com/v2.7/?fields=id,share,og_object{engageme
You can use the query
https://graph.facebook.com?id=&fields=og_object{engagement}
The answer will be
{ "og_object": { "engagement": { "count": 197, "social_sentence": "197 people like this." }, "id": "895062470590407" }, "id": "" }
og_object->engagement->count total shares here
og_object->engagement->count