Generated by SassMeister.com.

input.scss

@mixin is-rtl() {
    @at-root [dir="rtl"]#{&} {
       @content;
    }
}

.selector {
    background: red;
    
    @include is-rtl() {
        background: olive;
    }
    
    [lang="en"] & {
        background: green;
        
        @include is-rtl() {
            background: olive;
        }
    }
}

output.css

.selector {
  background: red;
}
[dir=rtl].selector {
  background: olive;
}

[lang=en] .selector {
  background: green;
}
[dir=rtl][lang=en] .selector {
  background: olive;
}

settings.json

{
  "sass": {
    "compiler": "dart-sass/1.26.11",
    "extensions": {},
    "syntax": "SCSS",
    "outputStyle": "expanded"
  },
  "autoprefixer": false
}