Q:

How do I filter out 'items' that don't match search result?

Show items with the same value as the search input, and hide if the value isn't the same.  
var item = { 
    Image: itemImage, 
    Title: itemTitle, 
    Price: itemPrice, 
    Location: itemLocation, 
    Name: itemName 
};

function Search() {
    var z = document.getElementById('inputSearch').value;
    if (z == itemTitle)
}

A:

What you want is search results updating in realtime. Look at this example, the search results will hide the results which if the value in not same.

function myFunction() {
    var input, filter, ul, li, a, i, txtValue;
    input = document.getElementById("myInput");
    filter = input.value.toUpperCase();
    ul = document.getElementById("myUL");
    li = ul.getElementsByTagName("li");
    for (i = 0; i < li.length; i++) {
        a = li[i].getElementsByTagName("p")[0];
        txtValue = a.textContent || a.innerText;
        if (txtValue.toUpperCase().indexOf(filter) > -1) {
            li[i].style.display = "";
        } else {
            li[i].style.display = "none";
        }
    }
}
<input type="text" id="myInput" onkeyup="myFunction()" placeholder="Search for names.." title="Type in a name">

<ul id="myUL" style="list-style: none;">
  <li><p href="#">Adele</p></li>
  <li><p href="#">Agnes</p></li>
  <li><p href="#">Billy</p></li>
  <li><p href="#">Bob</p></li>
  <li><p href="#">Calvin</p></li>
  <li><p href="#">Christina</p></li>
  <li><p href="#">Cindy</p></li>
</ul>

more on that: https://www.w3schools.com/howto/howto_js_filter_lists.asp

