merge.ts

  ngAfterViewInit() {
  
   let o1:Observable<boolean> = this.cb1.valueChanges;
   let o2:Observable<boolean> = this.cb2.valueChanges;

   merge(o1, o2).subscribe( v=>{
   let cb1Value = this.cb1.value;
   let cb2Value = this.cb2.value;  
   this.cbValues = {
        cb1: cb1Value,
        cb2: cb2Value
      }
      console.log(this.cbValues);
    });
  }