Creating a transparent navbar is very easy - just don't add a color class .bg-* to the navbar.
In this case, the Navbar will take the color of the parent's background color.
<!-- Navbar -->
<nav class="navbar navbar-expand-lg navbar-light">
<!-- Container wrapper -->
<div class="container-fluid">
<!-- Navbar brand -->
<a class="navbar-brand" href="#">Brand</a>
<!-- Toggle button -->
<button
class="navbar-toggler"
type="button"
data-mdb-toggle="collapse"
data-mdb-target="#navbarSupportedContent"
aria-controls="navbarSupportedContent"
aria-expanded="false"
aria-label="Toggle navigation"
>
<i class="fas fa-bars"></i>
</button>
<!-- Collapsible wrapper -->
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<!-- Left links -->
<ul class="navbar-nav me-auto mb-2 mb-lg-0">
<li class="nav-item">
<a class="nav-link active" aria-current="page" href="#">Home</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
<!-- Navbar dropdown -->
<li class="nav-item dropdown">
<a
class="nav-link dropdown-toggle"
href="#"
id="navbarDropdown"
role="button"
data-mdb-toggle="dropdown"
aria-expanded="false"
>
Dropdown
</a>
<!-- Dropdown menu -->
<ul class="dropdown-menu" aria-labelledby="navbarDropdown">
<li>
<a class="dropdown-item" href="#">Action</a>
</li>
<li>
<a class="dropdown-item" href="#">Another action</a>
</li>
<li><hr class="dropdown-divider" /></li>
<li>
<a class="dropdown-item" href="#">Something else here</a>
</li>
</ul>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true"
>Disabled</a
>
</li>
</ul>
<!-- Left links -->
</div>
<!-- Collapsible wrapper -->
</div>
<!-- Container wrapper -->
</nav>
<!-- Navbar -->