The Hivebusters Add-on for Gears 5 has 15 achievements worth 90 gamerscore.
As Keegan, activate Resupply ability 25 times in the Hivebuster Campaign Expansion
Unlock during the DLC Campaign
Activate Keegan, Lahni and Mac's Abilities in the Hivebuster Campaign Expansion
Kill 50 enemies using Lahni's Electroblade Ability as Lahni in the Hivebuster Campaign Expansion
Kill 50 enemies as Mac through your Barrier Ability in the Hivebuster Campaign Expansion
Complete all Chapters of the Hivebusters DLC (any difficulty)
Complete all Chapters of the Hivebusters DLC on Insane
Find all Character Ability upgrades in the Hivebusters DLC
Complete the Hivebusters DLC in 3-Player Co-Op (Scorpio squad, dupes not allowed)
Collect all Campaign Collectibles in the Hivebusters DLC