Data Class' properties call in exact order Kotlin

So I have a kotlin data class (model) representing a JSON object (for retrofit's GSON converter), and I want to iterate through my model in a certain order for further creating a listView of JSON data.

The Model has nesting with ArrayLists.

Model.kt

object Model {
    data class Result(
        val results: ArrayList<Results>?,
        val syllables: Syllables,
        ...)
    data class Results(
        val definition: String,
        val partOfSpeech: String,
        val synonyms: ArrayList<String>?,
        val antonyms: ArrayList<String>?,
        ...)

I have tried to do some reflections but didn't realize how to iterate through Results ArrayList. Something like that (error occurs: ArrayList can't be cast to Model.Results):

class CallOrder(private val obj: Model.Result) {
        fun getOrder(): List<String> {
            val result = ArrayList<String>()
            for (prop in Model.Result::class.declaredMemberProperties) {
                if (prop.name == "results")
                    for (prop1 in Model.Results::class.declaredMemberProperties)
                        result.add("${prop1.name} = ${prop1.get(prop.get(this.obj) as Model.Results)}")
            }
            return result.subList(0, 1)
        }
    }

I want something to call like that:

CallOrder(obj, property1, property2, property3.property31).next() // returns obj.property1
CallOrder(obj, "property1", "property2", "property3.property31").next() // or to do the same with string representations (of attribute path)

Any ideas to implement that?