Hello,

First of all, we're dealing with "comprehensive market risk limits" (limites globales de risques de marché) which concern the establishment of boundaries, providing/allowing for different...
I'm not sure how to translate "niveaux d'agrégation."

I believe that "arborescence" stems from the verb "arborer", meaning "dresser" or "éléver" ("to set up" or "establish" in this context).

"Périmètres" are boundaries or limits of some sort, "s'appliquer" means "to concern."

I'll try to translate more of the sentence later on. But, for now, that's all I know.

Also, I don't think you should use "limits" twice in such a short sentence. The French doesn't, and you shouldn't either if it's possible to find an appropriate synonym.

I hope this helps.