You can delete your dashboards anytime.
Deleting a dashboard deletes all KPIs and the alerts associated with them.
You must have access to the dashboard and appropriate rights to delete it. For details, see User Roles and Share Dashboards.
Insights do not get deleted. To delete an insight, go to Analytical Designer.
To delete a KPI:
Switch to the Dashboards section.
Select your dashboard from the list of dashboards.
Click the three dots and select Delete and confirm. The dashboard is deleted.