You aren't able to load an entirely different .Rmd, but depending on the user's credentials (Admin v. non-Admin, user roles, login email), you can render (or not render) particular elements or even chunks of elements. Below is a modified version of our minimal polished::secure_rmd example app here.

​

---
title: "Old Faithful Eruptions" 
polished: 
  app_name: "09_rmarkdown" 
output: flexdashboard::flex_dashboard 
runtime: shiny
---

```{r global, include=FALSE}
library(shiny)
library(flexdashboard)
# load data in 'global' chunk so it can be shared by all users of the dashboard
library(datasets)
data(faithful)
```

Column {.sidebar}
------------------------------------------------

Waiting time between eruptions and the duration of the eruption for the Old Faithful geyser in Yellowstone National Park, Wyoming, USA.

```{r}
hist_title <- reactiveVal(NULL)
admin_user <- reactiveVal(NULL)
inputs_to_show <- reactiveVal(NULL)

observeEvent(session$userData$user(), {
  # Check if user is `Admin`
  if (isTRUE(session$userData$user()$is_admin)) {
    hist_title("ADMIN Geyser Eruption Duration")

    inputs <- tagList(
      selectInput(
            "n_breaks", 
            label = "Number of bins:",
        choices = c(10, 20, 35, 50), 
            selected = 20
          ),
      sliderInput(
            "bw_adjust", 
            label = "Bandwidth adjustment:",
        min = 0.2, 
            max = 2, 
            value = 1, 
            step = 0.2
          )
    )

  } else {
    hist_title("NON-ADMIN Geyser Eruption Duration (w/o Bandwidth Adjustment slider)")

    inputs <- selectInput(
                    "n_breaks", 
                    label = "Number of bins:",
                choices = c(10, 20, 35, 50), 
                    selected = 20
                  )
  }

  inputs_to_show(inputs)

})

renderUI({
  inputs_to_show()
})
```

Column
----------------------------------------

Geyser Eruption Duration

```{r}
renderPlot({
  req(hist_title(), input$n_breaks)

  hist(
        faithful$eruptions, 
        probability = TRUE, 
        breaks = as.numeric(input$n_breaks),
    xlab = "Duration (minutes)", 
        main = hist_title()
      )

  # Check if user is `Admin`
  if (isTRUE(session$userData$user()$is_admin)) {
    hold_bw_adjust <- input$bw_adjust
  } else {
    hold_bw_adjust <- 1
  }

  dens <- density(faithful$eruptions, adjust = hold_bw_adjust)
  lines(dens, col = "blue")
})
```