Where to put Pester Variables?

I've recently started using pester to write tests in powerShell and I've got not problem running basic tests, however I'm looking to build some more complex tests and I'm struggling on what to do with variables I need for the tests.

I'm writing tests to validate some cloud infrastructure, so after we've run a deployment it goes through and validates that it has deployed correctly and everything is where it should be. Because of this there are a large number of variables needed, VM Names, network names, subnet configurations etc. that we want to validate.

In normal PowerShell scripts these would be stored outside the script and fed in as parameters, but this doesn't seem to fit with the design of Pester or BDD, should I be hard coding these variables inside my tests? This doesn't seem very intuitive, especially if I might want to re-use these tests for other environments. I did experiment with storing them in an external JSON file and reading that into my test, but even then I need to hardcode the path to the JSON file in my script. Or am I doing it all wrong and there is a better approach?