Access only the table values in a user-defined field (UDF)

I'm trying to get to the list of values that are specified in a UDF. I'm following the examples laid out here:

https://developer.maximizer.com/discuss/65b06d5f39233e00558406db

Whenever I run the request in Postman, instead of getting the simple list of the 15 options in the UDF, I get the 43,000 selections of our 43,000 address book entries - most of which are null. The request that I'm sending is:

{
    "abEntry": {
        "criteria": {
            "searchQuery": {}
        },
        "scope": {
            "fields": {
                "KEY": 1,
                "Udf/$NAME(Restoration Group\\Network)": {
                        "Key": 1,
                        "DisplayValue": 1
                    }
            }
        }
    },
    "configuration": {
        "drivers": {
            "IAbEntrySearcher": "Maximizer.Model.Access.Sql.AbEntrySearcher"
        }
    },
    "compatibility": {
        "abEntryKey": "2.0"
    }
}

sending to: https://api.maximizer.com/octopus/AbEntryRead using the PAT.

How can I get just the 15 UDF options?