Is there an easy way to transfer to a tableau format(only keeps the parent level once)? I understand that the target format is not good in data science. But it makes the report easy to read. I can easily write it to excel and send the report to my boss..

```
library(data.table)
(dt <- data.table(Parent_Product=c("A","A","A","B","B","B"),
                 Sub_Product=c("red","red","blue","yellow","pink","pink"),
                 Sub_Product1=c(1,2,3,4,5,6),
                 Value=c(100,200,300,400,500,600)))

#>    Parent_Product Sub_Product Sub_Product1 Value
#> 1:              A         red            1   100
#> 2:              A         red            2   200
#> 3:              A        blue            3   300
#> 4:              B      yellow            4   400
#> 5:              B        pink            5   500
#> 6:              B        pink            6   600

(target_dt <- data.table(Parent_Product=c("A",NA,NA,"B",NA,NA),
                        Sub_Product=c("red",NA,"blue","yellow","pink",NA),
                        Sub_Product1=c(1,2,3,4,5,6),
                        Value=c(100,200,300,400,500,600)))

#>    Parent_Product Sub_Product Sub_Product1 Value
#> 1:              A         red            1   100
#> 2:           <NA>        <NA>            2   200
#> 3:           <NA>        blue            3   300
#> 4:              B      yellow            4   400
#> 5:           <NA>        pink            5   500
#> 6:           <NA>        <NA>            6   600

```