MovementTarget.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class MovementTarget : MonoBehaviour
{


    private Transform target;
    private Vector3 startPos;
    private Vector3 targetPos;
    private Vector3 tempTargetPos;

    private float speed = 2f;

    // Use this for initialization
    void Start()
    {

        target = transform.FindChild("Target");

        startPos = transform.position;
        targetPos = target.position;
        tempTargetPos = targetPos;

        target.parent = null;

    }

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

        transform.position = Vector3.MoveTowards(transform.position, targetPos, speed * Time.deltaTime);
    }

    private void FixedUpdate()
    {
        if( transform.position == targetPos)
        {
            if(targetPos == tempTargetPos)
            {
                targetPos = startPos;
            }
            else if(targetPos == startPos)
            {
                targetPos = tempTargetPos;
            }
        }
    }
}