This achievement requires managing the same Hero through several companion changes.
Here’s how it can be reproduced:

1. Build a Haven with your Hero and select a Companion.

2. Dismiss the Hero — the Haven will be destroyed, and the Companion will become Heartbroken.


3. (Re)hire the same Hero (as a Mercenary).


4. Build a new Haven and choose another Companion.

(Rinse and) Repeat the steps until the Hero has had three different Companions over the course of the same game.

🔹 It’s possible to notice that immediately after dismissing the Hero, the previous Companion will appear as Heartbroken among the Notables list.
🔹 Make sure to choose different companions until achievement notification appear. The 3rd one should do the trick...

• The Hero can be re-hired multiple times, each time building a new Haven and assigning a new Companion.
  
• Any Hero can achieve this — the specific name or faction does not matter.