Drupal 8 CiviCRM Entity and Views activities
Here's a working example of &quot;My Activities&quot;
Olly: you should just be able to change Assignee to Source for your use case (in Configure Relationship Contact)
Code: git repo -&gt; last commit -&gt;
commit bb1f503bd67d1537a16b28022a4f2444883ef231
Author: Rob Ellis &lt;&gt;
Date:   Sun Oct 11 23:21:17 2020 +0000

    Changed views contact subtype default arg to return &quot;&lt;none&gt;&quot; for users without a subtype