Dynamic checkboxGroupInput In R Shiny

I am trying to create 2 checkbox input group based on the user input, so that I can run a logic to plot it against each other. Now Ideally IF the user selects 2 options in group 1 it shouldn't appear in group 2 of the checkboxgroup. How do I implement this?

The Column names, when created by user is appearing properly in the checkbox group as expected, but it is not being dynamic. That is when One option is selected it is not disappearing from the second group

enter image description here

So when 2 options are selected in the first group, It should disappear from the second option

Providing the UI part

 uiOutput("ui_costs_choices"),
 uiOutput("ui_benefits_choices")

Providing the server part

#Defining the ui_costs_choices
  output$ui_costs_choices <- renderUI({
    req(rv$df)
    checkboxGroupInput("Costs", "Select the cost criteria:", choices = names(rv$df))
  })
  #Defining the ui_benefits_choices
  output$ui_benefits_choices <- renderUI({
    req(rv$df)
    checkboxGroupInput("Benefits", "Select the Benefits criteria:", choices = names(rv$df))
  })
  observeEvent(input$Costs, {
    req(rv$df)
    # Get the names of the columns in rv$df
    all_choices <- names(rv$df)
    # Remove the ones that are already selected as costs
    benefit_choices <- setdiff(all_choices, input$costs)
    # Update the benefit checkboxGroupInput with the remaining choices
    updateCheckboxGroupInput(session, "Benefits", choices = benefit_choices)
  })
  observeEvent(input$Benefits, {
    req(rv$df)
    # Get the names of the columns in rv$df
    all_choices <- names(rv$df)
    # Remove the ones that are already selected as benefits
    cost_choices <- setdiff(all_choices, input$benefits)
    # Update the cost checkboxGroupInput with the remaining choices
    updateCheckboxGroupInput(session, "Costs", choices = cost_choices)
  })

rv is a reactive object which contains the user entered values in the table in rv$df