Orchestrator API - Query Organization Units

Hi

I’m using the Orchestrator API to try and query all environments within a specified Organization Unit but I can’t find any documentation for this. I’m currently running Orchestrator 2017.1.

When I make a GET request to the following URL, https://{{host}}/odata/Environments, I get this response:
{
“message”: “An organization unit is required for this action.”,
“errorCode”: 1101
}

How can a specify an organization unit to perform the query on? I’ve looked at the Swagger documentation here but I can’t find any examples.

Thanks