I recently discovered that you can use tfe_outputs to extract state outputs from a given Terraform workspace.

Using workspace level permissions you can access the state programmatically across different workspaces.

data "tfe_outputs" "dns" {
  organization = "our-example-org"
  workspace    = "dns-workspace"
}

resource "aws_route53_zone" "dev_example" {
  name = "dev.example.com"
}

resource "aws_route53_record" "dev_example" {
  allow_overwrite = true
  name            = "dev.example.com"
  ttl             = 172800
  type            = "NS"
  zone_id         = aws_route53_zone.dev_example.zone_id

  records = [
    data.tfe_outputs.dns.values.example_nameservers
  ]
}