Items in AGOL are classified as layers, apps, web maps, etc. Please consider adding Operations Views as one of these types.
With the new web-centric Operations Dashboard that will be released in December, we have created a home page where you quickly get a filtered view of Dashboards created within your organization. I think this may satisfy your requirement to get a filtered view of Dashboards. You will just need to do it from the Home Page rather than filtering from your Content view.
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