You can block the user which you do not want to display chat to.
(1) After logging into Chat Plus's management screen, click on [Visitor] at the top of the screen.
(2) The list of visitor will be shown, so click on the user that you do not want to show the chat to.
(3) Click on [Edit] at the top right of the screen.
(4) Check in the box [Do not display the chat] and click on [Update].
(5) Check to see if the block mark is displayed.