2D Parallax Mouse Movement

I want to create a 2D parallax mouse movement in my project. It’s like the 2nd example shown here. The movement should only works in the x-direction.

The game is an escape-the-room game in first person. You can navigate only with your mouse.

I need one to three layers: background, shadows(additional) and foreground.

I’m really new in Unity and coding. So: are there any examples to learn (easily) or has anybody a hint (or maybe a solution)?

@herrgrab
Put this script on each UI object you want to parrallax and edit there modifier value accordingly:

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

public class MoveRelative2Mouse : MonoBehaviour {

    public Vector3 pz;
    public Vector3 StartPos;
    
    public int moveModifier;
    
	// Use this for initialization
	void Start ()
    {
        StartPos = transform.position;
    }
	
	// Update is called once per frame
	void Update ()
    {
        Vector3 pz = Camera.main.ScreenToViewportPoint(Input.mousePosition);
        pz.z = 0;
        gameObject.transform.position = pz;
        //Debug.Log("Mouse Position: " + pz);

        transform.position = new Vector3(StartPos.x + (pz.x * moveModifier), StartPos.y + (pz.y * moveModifier), 0);
        //move based on the starting position and its modified value.
    }
    
}