shinyTrees

app.R

library(shiny)
library(shinyTree)

ui <- fluidPage(
  shinyTree("tree"),
  hr(),
  shinyTree("tree1")
)

server <- function(input, output, session) {
  output$tree <- renderTree({
    list(
      a3=structure(list(
        a2=structure(list(
          a1=structure(list(""), stopened=TRUE)),
          stopened=TRUE)),
        stopened=TRUE))
  })
  output$tree1 <- renderTree({
    list(
      a3=list(
        a2=list(
          a1=structure(list(""), stopened=TRUE))
      )
    )
  })
}

shinyApp(ui, server)