By default, there are three prebuilt dashboards in the Performance tab.
You can remove the default dashboards or add more to the Performance page.
A dashboard will only appear on the Performance page when you manually add it there.
Add a Dashboard to Performance
From the Reporting tab, you can either create a new dashboard or edit an existing one.
Click Add to Performance area.
Once done, it now says Added to Performance area within the Dashboard.
You can now see the new Dashboard added to your Performance page.
📎NOTE: You can only add published dashboards to the Performance area. If it's still a draft, you're prompted to publish the dashboard so you can add it.
Remove a dashboard from Performance
Edit the dashboard: you can access the edit view from the Reporting tab or from Performance.
Untick the option "Add to Performance area"