Q. What is it supposed to be on the show?

A. A dance club.

 
Q. Where is it supposed to be on the show?

A.  On the roof of the Empire Hotel in New York City.

Q. When did we see it on the show?

A. In Episode 8 of Season One of Resurrection.

After meeting at the College of Criminology, Harrison and Gigi go out on a date together.

The scene opens with a fly-through of the huge, red “Empire Hotel” neon sign on the roof of the hotel. The zoom continues into a dance club on the hotel roof. We see a DJ mixing songs, flashing lights, and a crowd of young people dancing.

The scene then alternates between quick cuts of Gigi and Harrison dancing together in the crowd, and a conversation they are having over cocktails at a table off to the side.  She tells him that her dream of being a police officer is over, because the nerve damage to her arm is permanentsaved , so she would never make it through the police academy .

Harrison tells her that there are still opportunities in law enforcement, and that his father spent decades catching bad guys as a forensics blood-spatter analyst, without ever wearing a police uniform.

She's grateful for his sympathy, and the two end up in bed together.

The same rooftop shows up again briefly in Episode 9...

 

... ln a scene where we only see the huge,  red rooftop sign behind Harrison as he has a phone conversation with Dexter, giving him the details about Charley's threatening visit to his hotel.
 
But it's the same place: the rooftop of the Empire Hotel in New York City.

A. This is indeed the rooftop of the actual Empire Hotel in New York City, where Harrison works.

But in real life, the hotel does not have a dance club.  But it does have a rooftop worth visiting. 

On the roof of the Empire Hotel, you'll actually find The Empire Rooftop Bar, an 8,000-square-foot venue offering panoramic views of the city skyline (including Lincoln Center and Central Park). It is known for its chic atmosphere and was a filming location for the TV show Gossip Girl.  

   Yeah

It features multiple spaces, including the West Terrace with a retractable roof and a pool deck. The bar serves cocktails, has a food menu, and is open year-round (although the pool area is only open when the weather allows).

The Empire Hotel is located at 44 W 63rd St, on New York's Upper West Side.

You'll find their official website here.

 

 

 
Here is a matching StreetView of the Hotel:
 


Here is an aerial photo of the location.  And here is a map link.