Using Liquid variables with sql

[ivanKov]

I built a parameter and a measure which run SQL from a joined view, but when I run it in Explore, I get an error: "No such field joined_view.field1"

view: viewA {
   .
   .
   .
parameter: selection_field {
    type: unquoted
    allowed_value: {
      label: "1"
      value: "field1"
    }
    allowed_value: {
      label: "2"
      value: "field2"
    }
    allowed_value: {
      label: "3"
      value: "field3"
    }
  }
measure: dynamic_count {
    type: count_distinct
    label: "Selection"
    sql:
      ${joined_view.{% parameter selection_field %}};;
  }
}

When I try (below), it runs successfully. How to deal with it? Thanks for your help.

measure: count {
    type: count_distinct
    sql:
      ${joined_view.field1};;
  }