Will you have access to a car?
There is the Jack Daniel's distillery about an hour's drive South of Nashville in Lynchburg which do a very interesting tour. Miss Mary Bobo's is definitely worth going to for lunch but you do need to make a reservation as it is popular.
Belle Meade Plantation close to Nashville is another interesting place to visit.
If you and some colleagues fancy an escape room the Escape Game on Iris Drive in Berry Hill has some excellent rooms, I think they also have some at the Opry Mills mall.
The Opry Mill mall is an outlet mall and has some good bargains. The nearby Gaylord Opryland Resort is worth a visit just to see the hotel and gardens.
Olive and Sinclair chocolate only do tours on Saturdays, but they still sell their chocolate from their factory shop and that makes very good presents to take back for people. They mostly sell to pastry chefs so they don't have a wide range of products, but they are excellent. The white chocolate and the chili chocolate are particularly good.
Chauhans Ale and Massala House does Indian food with a Southern US twist e.g. chickent tikka and waffles.
There are the Cheekwood botanical gardens but I haven't been to them.
A replica of the Parthenon in Centennial Park (I still don't really understand why that is there, but it is).
Obviously there is a ton of live music in Nashville. I think it is based around Demonbreun Street. There is also the Country Music Hall of Fame.
The Frist Art Museum has interesting exhibits.