What is the nature and description of the request?

It would be useful to access inventory variables in the supported attributes for custom notifications, like it is happening already for summary_fields.inventory.name for instance.

Why does the customer need this? (List the business requirements here)

The customer uses inventory variables to categorize the servers and would like to access the information for the custom notifications (e.g. via mail). The currently available values are unfortunately not sufficient to achieve the desired effect.

How would you like to achieve this? (List the functional requirements here)

Source data available from:

https://<hostname>/#/inventories/inventory/<id>/hosts/<id>/details 
https://<hostname>/#/inventories/inventory/<id>/groups/<id>/details

Values are available in the "Variables" or "Artifacts" field.

This data, or part of it, could be made available under summary_fields.inventory.variables