Unfortunately, those values cannot be accessed anywhere else in Airtable. You can’t sort by those values, you can’t group by those values, you can’t use those values in formulas, you can’t even copy & paste them. They are for visual cosmetic purposes only, which makes them relatively useless.
You can recreate them by using multiple tables, linked records, and rollup fields, but still not the same thing.
Be sure to email support@airtable.com to request that they enhance the functionality of those values in the summary bars.