$map: (foo: 'b', bar: c);
$list: ('d', e);

a {
  #{map-get($map, foo)} & {
      foo: bar;
  }
  #{map-get($map, bar)} & {
      foo: bar;
  }

  #{nth($list, 1)} & {
      foo: bar;
  }

  #{nth($list, 2)} & {
      foo: bar;
  }
}