Multiple Display Ray casting example

SelectorScr.cs

using UnityEngine;
using UnityEngine.UI;

public class SelectorScr : MonoBehaviour
{
    public Camera myCam;
    private RaycastHit hit;
    private Ray ray;
    public Text selectedGOName;

    private void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            #if UNITY_EDITOR
            var mousePosInScreenCoords = Input.mousePosition;
            #else
            // Convert the global mouse position into a relative position for the current display 
            var mousePosInScreenCoords = Display.RelativeMouseAt(Input.mousePosition);
            #endif

            // z is the display Id
            if (mousePosInScreenCoords.z == myCam.targetDisplay)
            {
                ray = myCam.ScreenPointToRay(mousePosInScreenCoords);

                if (Physics.Raycast(ray, out hit))
                {
                    hit.collider.gameObject.SetActive(false);
                }
            }
        }
    }
}