Reference method from the nested object

Hello everyone,
In case of nested objects how can a method belonging to the parent object be accessed from the child object?

let topics = {
    chooseRandomly (arr){
        return arr[Math.floor(Math.random()*arr.length)]
    work : {
        topicActions : "Your actual job is ".concat(this.chooseRandomly(["Software Developer", "Network Engineer", "Recruiter", "Systems Engineer", "Physician", "Statistician", "Dentist"]))
}`Preformatted text`

Output: TypeError: Cannot read property ‘chooseRandomly’ of undefined

How can be accessed chooseRandomly method from work object?