ACDL eventing with built-in change event

acdl-test4.js

// In a browswer window with URL about:blank
// Open the JS console and paste this code

window.adobeDataLayer =  [];

adobeDataLayer.push({
    x: 1
});
adobeDataLayer.push({
    event: "test",
    y: "a"
});
adobeDataLayer.push({
    x: 2
});
adobeDataLayer.push({
    event: "test",
    y: "b"
});

adobeDataLayer.push(function (dl) {
    dl.addEventListener("adobeDataLayer:change", function(e) {
        console.log(e);
    }, {
        path: "x"
    });
});

var scriptElement = document.createElement('script');
scriptElement.src = "https://unpkg.com/@adobe/adobe-client-data-layer@2.0.1/dist/adobe-client-data-layer.js";
document.body.append(scriptElement);

// Console output will be:
// {x: 1}
// {x: 2}

If what you are interested in is tracking all changes done to the variable x, then you can define an event listener to track any changes done to that with the adobeDataLayer:change event that you can limit to the path x.