Today, i enabled an isolated search node cluster with 2 nodes for one of our cluster which is an multi-region cluster with 4 nodes in N.Virginia and 1 node in Oregon. I can see that search node cluster has added 2 nodes in N.Virginia and 2 nodes in Oregon.
We use N.Virginia as our primary region and Oregon as our secondary region mainly considering it (Oregon) only for Disaster recovery purposes, so having 2 search nodes in Oregon will not be of much use for us, and I don't see an option in the mongoDB Atlas console to configure the number of nodes I want in the corresponding regions as we are able to do for the main cluster.