Terraform nested for loop for_each

main.tf

locals {
  nested_loop = { for entry in flatten(values({
    for k, v in var.hub_networks :
    k => [
      for key, val in var.firewalls :
      merge(val, v, { "key" : "default-deny-${lower(val.direction)}-${v.network}" })
    ]
  })) : entry.key => entry }

}
    
hub_networks = {
  int = {
    project = "int"
    network = "int-network"
  }
  pre = {
    project = "pre"
    network = "pre-network"
  }
}

firewalls = {
  deny_egress = {
    direction = "EGRESS"
    priority  = 65535
  }
  deny_ingress = {
    direction = "INGRESS"
    priority  = 65534

  }
}