How to add tab sets into flexdashboard? - r

Question

I am working with flexdashboard and I am trying to add sub tabset into tabset . Below you can see my code:
---
title: "Test APPLICATION"
output:
flexdashboard::flex_dashboard:
orientation: columns
vertical_layout: fill
---
```{r setup, include=FALSE}
library(flexdashboard)
library(data.table)
library(tidyr)
library(dplyr)
library(tidyverse)
library(knitr)
library(DT)
library(rpivotTable)
library(biclust)
data(BicatYeast)
data=data.frame(data(BicatYeast))
```
# Intro
Testing application
Tabset 1
=======================================================================
Row {.tabset}
-----------------------------------------------------------------------
### Notes
### Sub tabset 1
```{r,eval=TRUE}
rpivotTable(
data,
aggregatorName = "Integer Sum",
vals="Total",
cols = "Test",
width="100%",
height="400px",
rendererName = "Table"
)
```
### Sub tabset 2
```{r,eval=TRUE}
rpivotTable(
data,
aggregatorName = "Integer Sum",
vals="Total",
cols = "Test",
width="100%",
height="400px",
rendererName = "Table"
)
```
Tabset 2
=======================================================================
Row {.tabset}
-----------------------------------------------------------------------
### Sub tabset 1
```{r,eval=TRUE}
datatable(data,
caption = "Test",
rownames = T,
filter = "top",
class = 'cell-border stripe',
extensions='Buttons',
options = list(
pageLength = 50,
dom = 'Blfrtip',
buttons=c('copy','csv','excel','pdf','print'),
lengthMenu = list(c(10,25,50,-1),c(10,25,50,"All"))
))
```
### Sub tabset 2
```{r,eval=TRUE}
datatable(data,
caption = "Test",
rownames = T,
filter = "top",
class = 'cell-border stripe',
extensions='Buttons',
options = list(
pageLength = 50,
dom = 'Blfrtip',
buttons=c('copy','csv','excel','pdf','print'),
lengthMenu = list(c(10,25,50,-1),c(10,25,50,"All"))
))
```
Now, I want to put additional tab sets under Sub tabset 1. Can anybody help me on how to solve this problem and add additional tab sets (two or three)?