Angular: How do I navigate to a sibling route?

 angular - How do I navigate to a sibling route? - Stack Overflow

Update 08/02/2019 Angular 7.1.0

current route: /department/7/employees/45/sales

the old version will do: /department/7/employees/45/sales/contacts

As per @KCarnaille's comment the above does not work with the latest Router. The new way is to add .parent to this.r so

    // Working(08/02/2019) 
    goToContact() {
       this.router.navigate(["../contacts"], { relativeTo: this.r.parent });
    }

the update will do: /department/7/employees/45/contacts