in R shiny, how to automatically or based on function tabPanel, given we have 3 levels of lists?

I need to create conditional 3 levels of tabs the first level or tabPanel includes three tabs
"NUTS","SWEETS","DRINKS"
so the

level1<-list(DRINKS,SWEETS,NUTS)

the second level or is conditional on the first level
for example after selecting DRINKS, would be juices, energydrinks, hotdrinks
the third level would be after selecting energy drinks to "powerhorse","redbull"

tried code but not working is this

lists -------------------------------------------------------------------

library(shiny)
library(reshape2)
library(dplyr)

hotdrinks<-list('hotdrinks'=list("tea","green tea")) 
juices<-list('juices'=list("orange","mango") )
energydrinks<-list('energydrinks'=list("powerhorse","redbull")) 
drinks<-list('drinks'=list(hotdrinks,juices,energydrinks))
biscuits<-list('bisc'=list("loacker","tuc"))
choc<-list('choc'=list("aftereight","lindt") )
gum<-list('gum'=list("trident","clortes") )
sweets<-list('sweets'=list(gum,juices,energydrinks))

almonds<-list('almonds'=list("salted","roasted") )
pistcio<-list('pistcio'=list("flavourd","roasted")) 
nuts<-list('nuts'=list(almonds,pistcio))

all_products<-list(sweets,nuts,drinks)
mt<-melt(all_products)

mt2<-mt%>%mutate("Price"=c(23,34,23,23,54,32,45,23,12,56,76,34,62,12,98,43),
          "Quantity"=c(10,20,26,22,51,52,45,23,12,56,76,55,62,12,98,43))

t1<-mt2[,c(5,3,1,8,7)]
t1
colnames(t1)<-c("CAT","PN","SP","Quantity","Price")

t2<-list(unique(t1$CAT))
t2

app ---------------------------------------------------------------------

library(shiny)

server <- function(input, output,session) {
  observe({print(input$t)})
  observe({print(input$u)})
  observe({print(input$v)})
  t3<-t1%>%filter(t1$CAT==input$t)
  print(t3)
  t4<-list(unique(t3$PN))
  print(t4)
  t5<-t3%>%filter(t3$PN==input$r)
  print(t5)
  t6<-list(unique(t5$SP))
  print(t6)
  t7<-reactive({
         t1%>%filter(t1$CAT==input$t,t1$PN==input$u,t1$SP==inptut$v)
         print(t7())
       })
  output$mytable <- DT::renderDataTable({
         t7
       })

  lapply(1:5, function(j) {
         DT::dataTableOutput("mytable")
       })
}

ui <- pageWithSidebar(
  headerPanel("xxx"),
  sidebarPanel(),
  mainPanel(
    do.call(tabsetPanel, c(id='t',lapply(unlist(t2), function(i) {
  tabPanel(
      do.call(tabsetPanel, c(id='u',lapply(unlist(t4), function(i) {
      tabPanel(
        do.call(tabsetPanel, c(id='v',lapply(unlist(t6), function(i) {
          tabPanel(DT::dataTableOutput("mytable")
              )
        })))
            
          )
        })))  
    
      )
    })))

  )
)
shinyApp(ui, server)