This can be earned in a regular game and is not specific to the Gift of the Nile scenario. This is relatively easy to earn and should take you no longer than 10 or 15 minutes to achieve.
Create a game using the following settings:
Starting Civ: Nubia
Start Era: Information
Game Speed: Online
Map: Pangea
Size: Any
Temperature: Hot
No Barbarians
Leave everything else as Standard.
You'll start with a few Settler units along with a few Rangers and Machine Guns. Use one of your Settlers to found a city next to a desert tile (Nubian Pyramids can only be build on desert or floodplains tiles), and use the other units to scout the immediate area. Use your other Settler units and found cities around 6-7 tiles away from your capital - this will aid in expanding the borders of your capital, making this achievement easier.
Then, produce a Builder in your Capital and use it to build a Nubian Pyramid on a desert tile next to your city. This'll earn you one adjacency bonus of +1 food. Now, it's simply a case of building five of the following districts around your Nubian Pyramid:
Campus (+1 Science)
Commercial Hub or Harbor (+1 Gold)
Holy Site (+1 Faith)
Industrial Zone (+1 Production)
Theatre Square (+1 Culture)
If the city next to where your Nubian Pyramid is struggling for population, run a few domestic trade routes from it to earn extra food and production which will aid in the city's growth.
If you're successful, you should end up with something like this: