You can Disable MySQL related charts from “Manage Dashboard charts” page.
Open Dashboard page –> On top-right corner you will see a link “Manage Dashboard Charts” click on it.
Now Select charts you do not want to see in Dashboard page and –> Click on “Disable”,
Similarly you can enable system related other charts from same page.
Note: These changes will be applied to all servers not specific to a particular server selected on Dashboard page,
Customization of charts on Dashboard page at server level is not implemented.