True, as you saw, we do not deliver "Datacenter" as a property of VM right now.
However - we do have a user-configurable property. You can use that.
The VM property "Segment" is actually populated from a Virtual Center custom attribute. If you create a global Custom Attribute in Virtual Center called "Veeam.segment", then it will be automatically gathered by the nworks MP, and the value placed in each VM Segment property.
You could put Datacenter name in the Custom Attribute, then you can use it in MP to populate Groups.
You can set this attribute manually for your VMs - or you can use the (free!) Veeam utility Business View to populate it automatically.
This is all explained in our MP Operations Guide - Appendix B "Integration with Veeam Business View".
Hope that helps - any questions let us know!
Vice President, Product Management