Metric extensions to notify on non-DBA notification schedule

I would like to allow application-level metric extensions to notify just the application notification schedule without also notifying the DBA notification schedule.

For example, currently the DBA Dev rule set has in it 4 rules.

1) "MX Dev" is to handle the specific listed metric extensions.

2) "Send WARNING alert" triggers on all metric alert events of severity = warning.

3) "Send SEVERE alert" triggers on all metric alert events of severity in (Critical, Fatal).

4) "ANY Target DOWN alert" triggers on all Target Availability = Down.

So when a metric extension of severity = warning triggers, the metric extension rule, MX Dev, fires and the application notification schedule, owned by MAXADMIN, is activated.  Good so far.   But after that rule completes, the DBA one, Send WARNING alert, ALSO fires because the metric alert is of severity “warning”.  I would like to only notify, on the notification schedule owned by MAXADMIN, when the MX Dev rule triggers.  Currently it fires as does the Send WARNING alert or Send SEVERE alert depending on the alert severity.