// promise that defines object and passes it to next function
function f1() {

    return new Promise((resolve, reject) => {
        var obj = {
            key1: "info",
            key2: "more info",
            etc: "and on and on..."
        };
        resolve(obj);
    });

}

// calls f1 and calls callback of f3 with new data from then of f1
function f2(cb) {

    f1().then((obj) => {
        console.log(obj); // Outputs actual values in obj as defined in f1
        cb.call(obj); // Successfully calls function, but "this" is not replaced with "obj" in callback
    })

}

// overarching function that initiates chain of events
function f3(cb) {
    f2(cb);
};

f3(() => {
    console.log(this); // Outputs an empty object
});