Magento 2 : scope of knockout JS variable

Here’s my code –

this.addresses = window.checkoutConfig.addresses;           this.phoenix.subscribe(function(someVal){             console.log("phoenix");             var group = someVal;             this.addresses.filter(function(el){                 console.log(el);                 return el.indexOf('abc');             });         }); 

Error: TypeError: this.addresses is undefined

As far as I understand, this.addresses is a global variable. Thanks