Hi smw,
To filter the data of the chart, there are two ways - 1) filter from the view, 2) filter form the chart. Both of them essentially adding filtering code to their respective fetch xml.
1. filter from the view.
When editing the dashboard, select the "Lost Opportunities" view before selecting the chart.

You don't need to create additional charts.
In this case, all the data in the chart are lost opportunities, so the number of opportunities in the chart is also the number of lost opportunities.
2. filter form the chart.
We could modify the xml of the chart to add filtering.
First open the chart in the dashboard and export it.

Open the xml file, find </entity>, add
<filter type="and">
<condition value="2" attribute="statecode" operator="eq" />
</filter>
before it.

Import it.

Switch the chart in the dashboard to the new imported chart.
This way, we can filter out lose opportunities without changing the original view range.