This would be the kind of thing to shout up under the 'Give your feedback' button in the bottom right of the dashboard. Not sure if it applies to this one (which appears to me more of a 'nice to have') but, if you have a request that's more business critical, I would reach out to your Cisco account team with details of what you're looking to achieve as a business and anything technical that you feels falls out of that.
What you could do with the current Dashboard functionality is add a set of prefixes for each group you want, in the Network names. That way if you had, for example, North, South, East & West prefixes, you'd just need to type that in the Dashboard and it would show you just those Networks.
While it wouldn't change anything in the Network > window, using different Network-level tags along similar lines might also help.