You can make a Chart available to only specific User Groups instead of public. Unselect the Public check box in the record view for the Chart, then, navigate to the User Groups tab and select the user group(s) that can use the Chart.
You can make a Chart available to only specific User Groups instead of public. Unselect the Public check box in the record view for the Chart, then, navigate to the User Groups tab and select the user group(s) that can use the Chart.