To share a dashboard, go to a project's home page & just click on the View button against the dashboard in Dashboards tab. This will direct you to the dashboard. On the top right side, below the title, you will find a drop down titled Export Dashboard. Click on an option to export the dashboard.
There are 3 ways to share a dashboard:
On exporting as PNG/PDF, you will be able to download a PNG/PDF file to your local machine.