SOURCE

let locations = {}
function format(arr) {
   arr.forEach(x => {
       if(x.children && x.children.length > 0) {
           let item = {}
           for ( let i=0;i<x.children.length;i++){
               item[x.children[i].value] = x.children[i].label
               locations[x.value] = item
               format(x.children)
           }
       } else { 
           return
       }
   }) 
}

format(result)

console.log(locations)