Hi Paul

You can use the RelationService to query relations setup on your site:

https://our.umbraco.org/documentation/reference/management/services/relationservice

The relate on copy will create entries in the Relations Section of your site under the alias 'relateDocumentOnCopy'

The original page id will be stored as the 'parent' of the relation and the copy page id will be stored as the 'child' in the relationship.

So for example in your partial view:

    @{
// get a reference to the relation service
    var rs = ApplicationContext.Current.Services.RelationService;
    // get a list of all relations caused by copying from the current node
        var copies = rs.GetByParentId(Model.Content.Id).Where(f => f.RelationType.Alias == "relateDocumentOnCopy").ToList();
// if this is the copied page see, if it is related to an original page
        var originals = rs.GetByChildId(Model.Content.Id).Where(f => f.RelationType.Alias == "relateDocumentOnCopy").ToList();

 //there should only be one original
        var originalRelation = originals.FirstOrDefault();
        }
        @if (copies.Any())
        {
            <h2>Copies</h2>
            foreach (var copyRelation in copies)
             {
// write out each node copied from this original
                     var copiedNode = Umbraco.TypedContent(copyRelation.ChildId);
                     if (copiedNode != null)
                     {
`// (you could check copiedNode.Path to see if it is located in the site you` want to link to)
                         <a href="@copiedNode.Url">@copiedNode.Name</a>
                     }
                 }
        }

       @if (originalRelation != null)
        {
// write out the original node this page was copied from
            var originalNode = Umbraco.TypedContent(originalRelation.ParentId);
            <h2>Original</h2>
         <a href="@originalNode.Url">@originalNode.Name</a>
        }

if that helps get you started ?

regards

Marc