SectionTrigger.cs

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

public class SectionTrigger : MonoBehaviour
{
    public GameObject nextSection;
    public GameObject previousSection;

    public void Forward()
    {
        nextSection.SetActive(false);
        previousSection.SetActive(true);
    }

    public void Backward()
    {
        nextSection.SetActive(true);
        previousSection.SetActive(false);
    }
}