ResetExample.cs

using UnityEngine;

[RequireComponent(typeof(Rigidbody), typeof(SphereCollider))]
public class ResetExample : MonoBehaviour
{
    [SerializeField] private Rigidbody rigidBody;
    [SerializeField] private SphereCollider sphereCollider;

#if UNITY_EDITOR
    private void Reset()
    {
        rigidBody = GetComponent<Rigidbody>();
        sphereCollider = GetComponent<SphereCollider>();
    }
#endif
}