Access object property that is outside of array

My page object is structured so that I have all of the elements in an object and then an array of objects containing data about the fields that can be looped over to test max char length and error texts.

I would like the locator to reference a property that is outside the array so that the value does not need to be updated twice if the element changed.

Snippet from page object as an example...

module.exports = {
    siteName: element(by.id('P662_NAME')),
    fields: [
        {
            name: 'site name',
            max: 45,
            locator: element(by.id('P662_NAME'))
        }
    ]
}

I have tried using the following with no luck...

this.siteName, this.siteName, module.exports.siteName

Is there a way to do this?