Добавив пару div
Добавлен marketing-main-header_banner_image для хранения изображения, которое может быть больше, чем marketing-main-header_banner.
Добавлено nav-держатель для размещения кнопки navbar-toggler в правильном месте.
html,
body {
height: 100%;
margin: 0px;
}
* {
box-sizing: border-box;
}
.marketing-main-header_banner {
overflow: hidden;
background-position: 100% 100%;
position: relative;
height: 900px;
width: 1700px;
}
.marketing-main-header_banner_image {
overflow: visible;
background-image: url("https://svgshare.com/i/8GY.svg");
background-size: cover;
background-repeat: no-repeat;
background-position: 100% 100%;
position: relative;
height: 900px;
width: 2000px;
}
.nav-holder {
background-position: 100% 100%;
position: relative;
height: 900px;
width: 1700px;
width: 1700;
}
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css">
<!-- jQuery library -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!-- Popper JS -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"></script>
<!-- Latest compiled JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"></script>
<div class="container-fluid marketing-main-header">
<div class="marketing-main-header_banner">
<div class="marketing-main-header_banner_image">
<div class="nav-holder">
<nav class="navbar navbar-expand-lg navbar-light">
<a class="navbar-brand" href="#">Navbar</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="navbar-nav ml-auto">
<li class="nav-item active">
<a class="nav-link" href="#">Dla kogo <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Agenda</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Prowadzacy</a>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#">Faq</a>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#">Kontakt</a>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#">Kompetencje</a>
</li>
</ul>
</div>
</nav>
</div>
</div>
</div>
</div>