How do you check if an invoicehas been back dated

I'm trying to use the value operations extension to check if the date_issue field is less than the documents arrived_by date. I.e. is the invoice backdated? The extension has no trouble finding the date_issue field but it is not able to find the arrived_by field I presume because it's in the documents metadata rather than the documents rir fields. Do you know a way of of referencing the documents arrived_by field when doing value operations. My value operations config currently looks like this:

{
  "operations": [
    {
      "condition": "{arrived_by} > {date_issue}",
      "target_field": "backdated",
      "default_value": "Yes",
      "condition_false_default_value": "No"
    }
  ]
}

This results in this error:

Schema ID 'arrived_by' not found in the document in Value Operations configuration:  
{'condition': '{arrived_by} > {date_issue}', 'target_field': 'backdated', 'default_value': 'Yes', 'condition_false_default_value': 'No'}

Any ideas?