increased_specificity.scss

@function index-of-last-class($selector) {
  $index: null;
  $counter: 1;
  @each $component in $selector {
    @if str-index($component, ".") == 1 {
      $index: $counter;
    }
    $counter: $counter + 1;
  }
  @return $index;
}
 
@function list-slice($list, $start, $end: length($list)) {
  $new-list: ();
  @for $i from $start through $end {
     $new-list: append($new-list, nth($list, $i), list-separator($list));
  }
  @return $new-list;
}
 
@mixin increased-specificity($selector) {
  @if length($selector) > 1 {
    @warn "Does not work on compound selectors at this time. Keeping the first.";
  }
  $selector: nth($selector, 1);
  $class-index: index-of-last-class($selector);
  @if $class-index {
    $before: list-slice($selector, 1, $class-index);
    $at: nth($selector,$class-index);
    $after: list-slice($selector, $class-index + 1, length($selector));
    $after: if(length($after) > 0, $after, null);
    @at-root #{$before}#{$at} #{$after} {
      @content;
    }
  }
  @else {
    @warn "Cannot increase the specificity of #{$selector}. It does not include a class name.";
    @content;
  }
}

.increase .me .please {
  @include increased-specificity(&) {
    content: wow;
  }
}