Getting position of an 3 D object ?

You can do that by typing this:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class ExampleOne : MonoBehaviour
 {
     public GameObject yourObject;
 
     void Update()
     {
         // Prints out position of your object every frame
         Debug.Log(yourObject.transform.position);
     }
 }

Or, if you really want to have the position be displayed on a UI text object, here is code for normal Unity's text:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class ExampleOne : MonoBehaviour
 {
     public GameObject yourObject;
 
     public Text yourNormalText;
 
     void Update()
     {
         // Sets the text of yourNormalText UI element to be yourObject's position (float). DON'T FORGET UnityEngine.UI NAMESPACE!!!
         yourNormalText.text = yourObject.transform.position.ToString();
 
         // Sets the text of yourNormalText UI element to be yourObject's position (int).
         yourNormalText.text = yourObject.transform.position.ToString("0");
     }
 }

Here is a bit better code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class ExampleOne : MonoBehaviour
 {
     public GameObject yourObject;
 
     public Text yourNormalText;
 
     void Update()
     {
         // Float
         yourNormalText.text = "X: " + yourObject.transform.position.x.ToString() + "  Y: " + yourObject.transform.position.y.ToString() + "  Z: " + yourObject.transform.position.ToString();
         
         // Int
         yourNormalText.text = "X: " + yourObject.transform.position.x.ToString("0") + "  Y: " + yourObject.transform.position.y.ToString("0") + "  Z: " + yourObject.transform.position.z.ToString("0");
     }
 }

Code for TextMeshPro:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using TMPro;
 
 public class ExampleOne : MonoBehaviour
 {
     public GameObject yourObject;
 
     public TextMeshProUGUI yourTextMeshProText;
 
     void Update()
     {
         // Sets the text of yourNormalText UI element to be yourObject's position (float). DON'T FORGET TMPro NAMESPACE!!!
         yourTextMeshProText.text = yourObject.transform.position.ToString();
 
         // Sets the text of yourNormalText UI element to be yourObject's position (int).
         yourTextMeshProText.text = yourObject.transform.position.ToString("0");
     }
 }

Bit better code for TextMeshPro:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using TMPro;
 
 public class ExampleOne : MonoBehaviour
 {
     public GameObject yourObject;
 
     public TextMeshProUGUI yourTextMeshProText;
 
     void Update()
     {
         // Float
         yourTextMeshProText.text = "X: " + yourObject.transform.position.x.ToString() + "  Y: " + yourObject.transform.position.y.ToString() + "  Z: " + yourObject.transform.position.ToString();
 
         // Int
         yourTextMeshProText.text = "X: " + yourObject.transform.position.x.ToString("0") + "  Y: " + yourObject.transform.position.y.ToString("0") + "  Z: " + yourObject.transform.position.z.ToString("0");
     }
 }

Hope you find this helpful!

Ok, it sounds like you want to get the position of your object in space relative to a camera object, at least that is what I understand from your question.

 [SerializeField]  private Transform camTransform; //this is your other camera transform
 
 [SerializeField] private Transform otherTransform; //this is your 3D object transform
 
 private Vector3 posRelativeToCam;
 
 private void Start()
 {
      posRelativeToCam = otherTransform.position - camTransform.position;
    
      Debug.Log(“Position relative to Camera “ + posRelativeToCam);
 }