Share Tab Groups and collaborate in Safari on Mac
You can share a Tab Group and collaborate with people who use iCloud. Everyone you collaborate with must be signed in with their Apple ID, have Safari turned on in iCloud settings and have two-factor authentication turned on.
Share a Tab Group
In the Safari app
on your Mac, place the pointer over a Tab Group in the sidebar, then click Share Tab Group.If the sidebar isn’t shown, click the Sidebar button
in the toolbar.Click Messages, then enter the person or group you want to share with.
You get activity updates in the Messages conversation when someone makes changes in the shared Tab Group. Click an update to go to the shared Tab Group.
Add and remove people from a Shared Tab Group
Participants can add and remove tabs from the Tab Group, and everyone sees updates in real time.
In the Safari app
on your Mac, click the Collaborate button 
in the toolbar.Click Manage Shared Tab Group, then do any of the following:
Remove someone: Click a name, then click Remove Access.
Add someone: Click Share with More people, then click Messages to invite them.
Stop sharing with everyone: Click Stop Sharing.
A Shared Tab Group can have a total of 100 participants.
Start a Messages, audio or video conversation from Safari
You can start a conversation — using Messages, FaceTime audio or FaceTime video — with everyone that shares the Tab Group, without leaving Safari.
In the Safari app
on your Mac, click the Collaborate button in the toolbar.Click message, audio or video to start the conversation.