"Relative reference" means referencing another field of a flow log to perform the filtering predicate, e.g.:

• To filter for flows within a given namespace:
  • filter key=SrcK8S_Namespace, match=exact, value="$DstK8S_Namespace"
• To filter for flows across namespaces:
  • filter key=SrcK8S_Namespace, match=exact_not, value="$DstK8S_Namespace"
  • (this involves a new "match type")

This is just a suggestion of API, other ideas welcome, but it shows the goal: be able to monitor traffic within bounds of X or across boundaries of X.

This would also be useful to monitor traffic cross-AZ