Some have layers, some don't
https://transparentgov.net/json2tree/esri/vendor/mappingsupport/url.html?url=https://transparentgov.net/data/live_data/csv/hub-site-only/combine-live-and-dead-shuffled.csv
Download data set and more
https://transparentgov.net/json2tree/esri/vendor/mappingsupport/dir.html?dir=./hub-site-only