Exodus Garden 2A is a Lost Sector than can be found on the Cosmodrome. To get there, you will need to spawn in near Shaw Han, then turn around go back through the buildings all the way to The Divide.
Go straight ahead, jump onto the low building and then up onto the large circular storage tank. From there, you can see the Lost Sector symbol etched in a wall near a hole. Jump inside and go straight ahead and you are on your way to the Lost Sector.
This Lost Sector is populated by Fallen enemies, and just like the others you will need to clear all enemies in each section to drop the shield and progress. There are plenty of Servitors to fight, and a couple of large Shanks.
The final boss is a massive Servitor in a circular arena, with some smaller Servitors floating around the outside. When you kill them all a door will open in the back, allowing you to quickly get back to the place you entered. Be careful though, as a large amount of Shanks will be waiting for you behind the door.
Once you have finished the Lost Sector at least once, and have gotten past 1200 Power, you will have the option to run the rotating Legend and Master difficulty versions of the Lost Sector to try and get new Exotics.