Modify your data structure and see if it is the result you want.

var obj = {"arr": [{"id": ["AttackArrow.json", "icon_effect1.json"]},{"id": ["effec_thudun.json"]}]}
function func(obj){
    for(i=0;i<obj.arr.length;i++){
        for(j=0;j<obj.arr[i].id.length;j++){
            if(obj.arr[i].id[j] == "AttackArrow.json"){
                return i,j
            }
        }
    }
}
func(obj);
console.log(i,j)

You can record the key set by adding an attribute to the target node when traversing the output