How do I check if JSON value is in list?

I am trying to check whether a certain string/value in a JSON is in a list/array but it does not work. What am i doing wrong?

This does work, but I don't just 2012 and Croatia, but all the data from the lists of years and countries:

    let countries = ["Croatia", "Italia", "Spain", "Greece", "Isreal", "Turkey"]
    let years = ["2012", "2013", "2014", "2015", "2016"]

    for (var i = 0; i < 3; i++) { 
        Object.values(finalDataset[i]).forEach(function(dataSep){
            // console.log(dataSep)
            for (var i = 0; i < Object.values(dataSep).length; i++){
                if ((Object.values(dataSep)[i].Time == "2012") || ((Object.values(dataSep)[i].Year == "2012"))){
                    if (Object.values(dataSep)[i].Country == "Croatia") {
                    var nation = Object.values(dataSep)[i].Country
                    var dataPoints = []
                    dataPoints.push(Object.values(dataSep)[i].Datapoint)
                    console.log(nation, dataPoints)
                    }           
                }
            }
        })
    }  

I tried:

            for (var i = 0; i < Object.values(dataSep).length; i++){
                if ((Object.values(dataSep)[i].Time in years ) || ((Object.values(dataSep)[i].Year in years))){
                    if (Object.values(dataSep)[i].Country in countries) {
                    var nation = Object.values(dataSep)[i].Country
                    var dataPoints = []
                    dataPoints.push(Object.values(dataSep)[i].Datapoint)
                    console.log(nation, dataPoints)
                    }           
                }
            }

but this doesnt work