Now, when I click the follow button, the workflow works, but I want the person followed to disappear and the suggestion list should get updated with new user to follow.
The database have to be set in the right way. So I assume you have a list with users that Current User Follows and a list of users that Current user is FOLLOWED BY (in the screen example its followers)
In that case just set the data source of the repeating group to:
You should change the data from Name to user. Because in the future you may need more information from the user. Imagine a particular user changes its username (assuming that it is what you are saving) the user will appear as if it is not followed. So my advice is change the data from to user.