Step 1: start the Divine Fragmentation quest
To start the quest, travel to the Lunar Battlefields. This location connects to the Harbor of Sorrow area through the red bridge on the right side, about halfway down the location itself.
The bridge you need is located on the map above next to my cursor. Once you get to the Lunar Battlefields, turn left and you will see a rather large cave in the rock in front of you. Go inside and follow the path to the end.
You will reach the giant Vex Gate, where you need to destroy three waves of enemies and a boss. Fortunately, the boss is not very difficult and you can do it quite well with the help of the grenade launcher. As soon as you do this, an Exotic Engram will appear - pick it up to start the Divine Fragmentation quest.
Step 2: analyze the Vex Kernels
The description tells you that you need to analyze the Vex Cores to understand what the Fragment is for, but there are none on the Moon. You must go to Lost Sectors, analyze the kernels and kill the Vex.
Travel to the Ness region on the Platform and visit the Confluence Sector (the entrance is marked with a red box above).
Once in the sector, look up and to the right where you will find a small niche. Jump up there and you will find the Core. Activate it, then kill Vex and interact with the Core to get 33% progress on fragmentation analysis. In the image above, the entrance to the Fusion sector itself is shown on the right, and the entrance to the small room you are looking for is on the left.
Respawn at the Edge of the Artifact, jump down and go to the Lost Sector on the left. When you reach the stairs leading to the boss, look up and to the left. The room you want is hidden in the shadows above you, so climb up and repeat the same process as the first time.
Go to the sector in the northwest of the Node. Immediately after meeting Pakrion, you will see a small cave on the left. Vex core inside.
Step 3: collect the parts of the Separating Sol
You need to collect 120 pieces of the Separating Salt. Just go to the "Vex Offensive"And start collecting killed enemies. Each will give you a chunk of the defrag kernel, you need 120.
Step 4: buy the Core
Respawn at Eris Morn, go to the Lectern of Enchantment (to the left of Eris, looks like an altar) and buy the Empowered Decryption Core for 30 Fragmenters. If you are looking for fragmenters, I would suggest you just farm Nightmares in Sorrow's Haven.
Step 5: Go to the Garden of Salvation Raid and solve the tethered puzzles
In the Garden of Salvation, you have to solve seven puzzles, each of which revolves around the mechanics of the leash. You need all six players to be connected to each other by different "cables"
To start the assignment, make sure you have followed the above steps. At the beginning of the raid, go down the cliff, turn around and find a hidden room. There is a node here that needs to be activated using a previously purchased kernel.
As for solving riddles directly, it is better to show than to explain, since they involve placing players according to certain patterns. I recommend watching this video by user Datto - starting at 3:00 - which showcases the puzzle locations and their solutions:
After all seven puzzles are solved - it is proposed to do it in one go - kill the last boss, and take away valuable loot, among which is a chest with a rifle.