How can "Box Collider is trigger" apply to the Player, not the enemies (make them collide, not pass through)?

Question

So, in my game, the Powerup (capsule) has a RigidBody and a Box Collider. I’ve set the Box Collider to «is trigger». When the player hits the powerup, it disappears - just as it’s supposed to.

Is it possible to let the enemies collide with the powerup (bump into it) instead of just passing through it? From the Enemy script:

    void Start()
{

        enemyRb = GetComponent<Rigidbody>();
        gameManager = GameObject.Find("GameManager").GetComponent<GameManager>();
        player = GameObject.Find("Player");

}

// Update is called once per frame
void Update()
{

    if (player != null && gameManager.isGameActive)
    {
        enemyRb.AddForce((player.transform.position - transform.position).normalized * speed);
    }

    if (transform.position.y < -4)
    {
        Destroy(gameObject);
        gameManager.UpdateScore(pointValue);
    }
}

From the PlayerController script:

private void OnTriggerEnter(Collider other)
{
        if (other.CompareTag("Powerup"))
        {
            hasPowerup = true;
            Destroy(other.gameObject);
        }
}

Answer 1

Firstly, i would recommend to move OnTriggerEnter from PlayerController to PowerupController:

private void OnTriggerEnter(Collider other)
{
        if (other.CompareTag("Player"))
        {
            other.GetComponent<PlayerController>().HasPowerup = true;
            Destroy(gameObject);
        }
}

It is not character's job to detect and destroy powerups; it would be better not to clutter characters scripts with additional logic when possible.

Now to collisions.

The best way is to use layers: https://docs.unity3d.com/Manual/LayerBasedCollision.html

Simply attach another collider as a child gameobject to powerup and set it physics layer to intersect with enemies and not intersect with the player.

... Or you could use OnCollisionEnter(Collision other) instead of triggers, but using triggers almost always is better idea.