This depends on your settings.
The standard setting allows all users to be able to see your newly created comment.
However, you can determine who is allowed to see the comment: only you, all users in the document or selected users.
If you choose selected users, proceeds as follows:
Choose “Selected” for the visibility setting from the drop-down menu.
A dialogue box opens and you can place a check by the users who should see the comment.
The users are selected by clicking on “Ok.”
You can still add users later by clicking below on “Add user” in the opened comment and proceed as described above.
You can also remove users from the comment by removing the check.