Change value from a line in table view

Question

I'm developing dashboards on grafana using Loki.

Question : How do I change this value so that one becomes FR (originally AuthStormShield-ChildStormShield ) & the other US (originally AuthSecondaire-ChildSecondaire) via a regex ? (because value mapping doesn't work)

Table View

I haven't succeeded and I don't think it's easy.

Thanks in advance for your answers

Value mapping doesn't work.