<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
</head>
<body>
<div id="here"><div class="string">
<input name="one">
<input name="two">
</div></div>
<span id="add">ADD</span>
<script>
$('#add').click(function(){
$('#here').append('<div class="string"><input name="one"><input name="two"><div onclick="$(this).parent().remove();">×</div></div>');
});
</script>
</body>
</html>
крестик внутрь