Google charts HTML tooltip for Sankey

I am using Google charts to display a Sankey diagram on my webpage. On clicking each link I would like the page to redirect to another page.

The problem is the 'select' handler in Sankey is not working, and is a known issue. To overcome this I added a HTML tool-tip to my links and gave a button, such that if user clicks the button then they are redirected to next page.

The problem with this solution is that I am unable to control where the tool-tip appears, so for certain links the tool-tip appears above the link. In this case the user can never reach the button because the tool-tip disappears the moment they move away from the link.

Can you please suggest a solution to either the original problem, or this tool-tip side effect?

via Chebli Mohamed