Dresden Hauptbahnhof is a railway station, not an airport, so the direct answer to any dresden airport lounge question aimed at this address is that there is no airport lounge here because there is no airport: this is Dresden's main train station, the hub for regional and long-distance rail service in and out of the city, whichever program or membership prompted the search.
For actual air travel from Dresden, the city's own airport is Dresden Airport, a modestly sized facility a short distance from the city center that handles domestic and a limited range of international routes. Lounge provision at an airport this size tends to be limited, so do not expect an elaborate premium space; confirm directly with your airline whether any lounge or fast-track option currently applies before building it into your plans, since smaller regional airports update these details less often than major hubs.
If a fuller lounge picture matters more to your trip than convenience, Berlin is the realistic upgrade. Berlin Brandenburg Airport, roughly two hours from Dresden by train or road, is Germany's newer major hub for the capital region and carries a substantially larger network of airline and membership lounges than Dresden's own airport can offer, reflecting its role serving both domestic connections and a wide range of international routes across Europe and beyond.
For travelers actually passing through Dresden Hauptbahnhof itself, the practical picture is standard train-station amenities, seating, food and retail options, and connections to onward rail service, rather than anything resembling an airport lounge. If your journey continues by air, route your lounge expectations toward Dresden Airport for a limited option or Berlin Brandenburg for a fuller one, and check your specific airline or membership program's current terms at whichever you actually fly through, ideally before you leave home, so nothing about the transfer catches you off guard.