CloudHSM Key Hierarchy

In simple terms, what is the key hierarchy in CloudHSM for actually encrypting data. I found this very easily for AWS KMS...... Domain Key > HBK/KMS Key > Data encryption Key (with exportable key tokens in the mix).

I can find no similar explanation in the literature for CloudHSM. I have gone through blogs, user guide, FAQs etc. What's the top key and how does it work it's way down in the envelope process from there. If this can be found in a link it would be great if someone could pass it along. I have been looking for quite some time. Thanks.