Want to same attribute on multiple place in moongoose

{
    username:{
        type: String,
        max: 12,
        min: 4,
        default: "Instagram User"
    },
    userId:{
        type: String,
        unique: true
    },
    email:{
        type: String,
        unique:true
    },
    password:{
        type: String,
        min:6,
        select: false
    },
    dob:{
        type: String,
        required: true
    },
    profilePic:{
        type:String,
        default:"/image/avatar.jpg"
    },
    follower:[{
        followerId:{
            type:String,
        },
        followerName:{
            type:String,
        },
        followerPic:{
            type:String,
        }
    }],
    following:[{

        followingId:{
            type:String,
            default: "__I want same objectId here__"
        },
        followingName:{
            type:String,
            default:"**Same username here**"
        },
        followingPic:{
            type:String,
            default:"**same profile pic here**"
        }
    }],
    
}