When dealing with messaging systems, you typically don't want spans trying to encapsulate the processing of messages that you don't have control over, so rather than having a parent/child relationship, links can be used instead.
The dashboard does not currently display links in the details view for spans.
Also linked spans are not shown unless they have the same TraceID and it's unclear if that will always happen in a message based system.

We should :-

1. Add a section for linked spans to the details of a span- and make it transitive, so show the links to the currrent span, and from the current span (they may not be the same)
2. Consider adding linked spans to the trace view to show the other spans that current ones are linked to.