Linking An Entity To A Collection Of Entities?

Hello.

I'm wondering how to save a reference to a collection of entities. In a traditional OOP game, you could have something like:

Code (CSharp):

1.  
2. public class Ship : MonoBehaviour
3. {
4.     private Dictionary<int, GameObject> enemiesInRange;
5.     void AddEnemy(int enemyID, GameObject enemy)
6.     {
7.         enemiesInRange.Add(enemyID, enemy);
8.     }
9.     void RemoveEnemy(int enemyId)
10.     {
11.         if (enemiesInRange.ContainsKey(enemyId))
12.         {
13.             enemiesInRange.Remove(enemyId);
14.         }
15.     }
16. }
17.  

What is the best approach for something like that on an ECS framework? Can I use a NativeHashMap on ComponentData to keep track of a bunch of entities? Should I be using a dynamic buffer instead?

To be more specific about my problem: I am using a hybrid approach and using a MonoBehaviour with OnTriggerEnter and OnTriggerExit to detect collisions with gameobjects in the scene. I then attach a CollisionData component to my colliding object, and I need to save a reference to all GameObjectEntity intersecting with that object. A Hashtable with Allocation.Persistent could do the trick, but is it better to use a dynamic buffer in this case?