如何在 jquery & bootstrap 5 中的主要固定顶部导航栏下的特定部分的滚动上添加第二个粘性导航栏？

Question

I have a page with one fixed-top navbar. Then I have 3 sections. In 2nd section I have nav-tabs. Upon scrolling into the 2nd section, I want the nav-tabs navbar to stick to top, below my fixed-top navbar. When user has scrolled out of the 2nd section, the nav-tabs navbar should disappear and only the fixed-top navbar must remain.

I can not find any tutorials or guidance related to what I'm trying to achieve. Any idea how to do this in bootstrap 5 using jquery?

index.html 
  <nav class="navbar navbar-expand-lg fixed-top">
    <div class="container-fluid">
      <a class="navbar-brand m-1" href="#intro">Tarheeb EMS Presentation</a>
      <button class="navbar-toggler collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#navbarMain"
        aria-controls="navbarMain" aria-expanded="false" aria-label="Toggle navigation">
        <span></span>
        <span></span>
            <span></span>
      </button>
      <div class="collapse navbar-collapse" id="navbarMain">
        <ul class="navbar-nav ms-auto mb-2 mb-lg-0">

          <li class="nav-item">
            <a class="nav-link" href="#">Introduction</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Platforms</a>
          </li>
           
          <li class="nav-item">
            <a class="nav-link" href="#">Comparison</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Summary</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Contact</a>
          </li>
          </li>
        </ul>
      </div>
  </nav>


  <section class="1">
  ....
  </section>

   <section class="2">
    <nav>
      <div class="nav nav-tabs sticky" id="nav-tab" role="tablist">

          <button class="nav-link active" id="nav-cvent-tab" data-bs-toggle="tab" data-bs-target="#nav-cvent"
          type="button" role="tab" aria-controls="nav-contact" aria-selected="false">Cvent</button>
          <button class="nav-link active" id="nav-cvent-tab" data-bs-toggle="tab" data-bs-target="#nav-cvent"
          type="button" role="tab" aria-controls="nav-contact" aria-selected="false">Cvent</button>
          <button class="nav-link active" id="nav-cvent-tab" data-bs-toggle="tab" data-bs-target="#nav-cvent"
          type="button" role="tab" aria-controls="nav-contact" aria-selected="false">Cvent</button>
          <button class="nav-link active" id="nav-cvent-tab" data-bs-toggle="tab" data-bs-target="#nav-cvent"
          type="button" role="tab" aria-controls="nav-contact" aria-selected="false">Cvent</button>
          <button class="nav-link active" id="nav-cvent-tab" data-bs-toggle="tab" data-bs-target="#nav-cvent"
          type="button" role="tab" aria-controls="nav-contact" aria-selected="false">Cvent</button>
          
      </div>
    </nav>
    <div class="tab-content" id="nav-tabContent">
    <div class="tab-pane fade show active" id="nav-cvent" role="tabpanel" aria-labelledby="nav-cvent-tab">
    </div>
     <div class="tab-pane fade show active" id="nav-cvent" role="tabpanel" aria-labelledby="nav-cvent-tab">
    </div>
     <div class="tab-pane fade show active" id="nav-cvent" role="tabpanel" aria-labelledby="nav-cvent-tab">
    </div>
     <div class="tab-pane fade show active" id="nav-cvent" role="tabpanel" aria-labelledby="nav-cvent-tab">
    </div>
     <div class="tab-pane fade show active" id="nav-cvent" role="tabpanel" aria-labelledby="nav-cvent-tab">
    </div>
    </div>
  </section>


  <section class="3">
  ...
  </section>

Answer 1

You can achive this by having primary navbar fixed or sticky does not matter. Just set the position of the required heading to position-sticky not sticky-top which sticks to top which you don't want. what you want is a secondary nav bar below the primary so css is helpfull set top to 12% or whatever you need just test it. This is jsFiddle link.

<section>
    <h1>Section 1</h1>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Molestias, sint fuga ipsam soluta maxime in est ipsa modi explicabo impedit natus, dolore eum, voluptas sequi dicta ullam placeat expedita quos.</p>
</section>
<section>
    <h1 class="position-sticky" style="z-index: 2;top:10%">Section 2</h1>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Molestias, sint fuga ipsam soluta maxime in est ipsa modi explicabo impedit natus, dolore eum, voluptas sequi dicta ullam placeat expedita quos.</p>
</section>
<section>
    <h1>Section 3</h1>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Molestias, sint fuga ipsam soluta maxime in est ipsa modi explicabo impedit natus, dolore eum, voluptas sequi dicta ullam placeat expedita quos.</p>
</section>