Cascading dropdown list - 3 level

Question

do you know how can I create a 3 level (or more) cascading drop-down?

I already have a reference for 2 level cascading drop-down

Creating a cascading drop down list in SharePoint Infopath 2013.

Answer 1

You can use SPServices to create a 3 level cascading dropdown:

<script src="https://code.jquery.com/jquery-3.2.1.min.js" type="text/javascript"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.SPServices/2014.02/jquery.SPServices-2014.02.min.js"></script>
<script language="javascript" type="text/javascript">
$(document).ready(function() {
  $().SPServices.SPCascadeDropdowns({
    relationshipList: "State",
    relationshipListParentColumn: "Country",    
    relationshipListChildColumn: "Title",
    parentColumn: "Country",
    childColumn: "State",
    debug: true
  });
  $().SPServices.SPCascadeDropdowns({
    relationshipList: "City",
    relationshipListParentColumn: "State", 
    relationshipListChildColumn: "Title",       
    relationshipListSortColumn: "ID",
    parentColumn: "State",
    childColumn: "City"
  });
});
</script>

More information check the video: Cascading Drop Down in SharePoint.