Instagram understands that our accounts have come to a point where we share a lot of our lives with everyone - but they also know some moments might want to only be shared with your "inner circle" - This is what Instagram said
“Instagram Stories has become the place to express yourself and share everyday moments, but our community has grown and sometimes what you want to share isn’t for everyone,” - “With Close Friends, you have the flexibility to share more personal moments with a smaller group that you choose.”
Here is how it works - Tap the “Close Friends List” option in the side menu on the right side of the app to create or add people to the list. The list is private and only the creator can add friends or see who is on it. If someone is on another user’s close friends list, a green ring will appear around their photo in the Stories section of the app. They’ll also see a green badge when viewing that person’s Stories.