Delete Custom Metrics
You can delete custom metrics from a data source in the Custom Metrics tab on the Fields tab, or by deleting the source entirely.
You can't delete a custom metric if it is used by any visuals, materialized views, actions, or chart defaults.
If you delete a source, your custom metric can't be used by associated visuals, materialized views, actions, or chart defaults.
To delete custom metrics from a data source while editing the data source configuration:
Edit the data source configuration in the UI. See Edit a Data Source Configuration.
Select the Fields tab.
Select Custom Metrics to open the Custom Metrics tab.
Locate the custom metric in the Custom Metrics table that you would like to remove.
Select the delete icon () in the Actions column.
Select Delete in the pop-up confirmation dialog. The custom metric is deleted if it is not in use.