It will be classed as zone 2 to 8, you've found one of BD's good value redemptions (i.e. going to HKG from Zone 2 is markedly cheaper than Zone 1) - the fact you transfer in Zone 1 isn't counted in this case either - it is the start & end point of redemptions that matter.

I'd recommend you read the forum sticky to look at things like "why cash and miles is good value", and "why you should never redeeem for Economy on BD" (almost all of the time)