let globalVar = [];
    const handler = {
        get(target, name) {
            const v = name in target ? target[name] : (target[name] = {});
            return typeof v == "object" ? new Proxy(v, handler) : v;
        },
        set(target, prop, val) { 
            if (prop == "a") {
                console.log("myObject["+prop+"] setto "+val);
            }
            else if (prop == "b") { //getting triggered 
                console.log("myObject["+prop+"] setto "+val);
            }
            else if (prop == "c") { //getting triggered 
                console.log("myObject["+prop+"] setto "+val);
            }
            else if (prop == "a.b") { //want to get something like this
                console.log("myObject["+prop+"] setto "+val);
            }
            target[prop] = val;
        }
    };
     globalVar = new Proxy(globalVar, handler);

    globalVar.a.x = "55a";
    globalVar.a.b = "55b";
    globalVar.a.c = "et4" ;