CME Globex, NYMEX, COMEX, and CBOT are exchanges operated by CME Group. Each exchange has its own set of symbols and each one has a separate subscriptions on TradingView. A subscription to each exchange gives you access to its regular and symbols. If you are buying a subscription with a specific symbol in mind, you can always look it up in the search field to see which subscription is required.
For example, to get real-time data for ES futures one would need CME E-mini real-time data. To get it, one should purchase the CME GLOBEX subscription.
To get real-time data for NG1! futures, one'd have to purchase the NYMEX data subscription.