Using custom variables for global server URI in OpenAPI scheme

I’m trying to prepare OpenAPI scheme in YAML format with global server parameter. But no matter how it’ll be setup, Postman will convert it to {{baseUrl}}, instead my custom parameter.

I tried and I know, it works with setting this parameter for each path. But can it be done globally?

Custom server URI with parameter (works with each path, but not as global):

servers:
  - url: '{server}'
    variables:
      server:
        default: https://custom.com