The dashboards you create and own are displayed under the My Dashboards category on the Navigation menu.
If you shared a dashboard with other users using the Access Control to Dashboards dialog box, that dashboard becomes a public dashboard and will also be displayed under the Public Dashboards category on the Navigation menu. The users with whom you shared the dashboard can then view that dashboard under the Public Dashboards category on their Navigation menus in read-only mode.
Configure access control to dashboards
Remove dashboards from My Dashboards