Generated by SassMeister.com.

input.scss

@mixin if-direct-parent($parent-selectors) {
    $current-sequences: &;
    $new-sequences: ();

    @each $parent-selector in $parent-selectors {
        @each $sequence in $current-sequences {
            $current-selector: nth($sequence, -1);
            $prepended-selector: join($parent-selector, $current-selector);
            $new-sequence: set-nth($sequence, -1, $prepended-selector);
            $new-sequences: append($new-sequences, $new-sequence, comma);
        }
    }

    @at-root #{$new-sequences} {
        @content;
    }
}

@mixin some-component-a {
    .some-component {
        
        display: inline;
        
        @include if-direct-parent(['body[lang=fr]']) {
            div {
                display: flex;
            }
        }
    
        & div {
            display: block;
        }
    
        &__span {
            display: inline-block;
        }
    }
}

html[brand="a"] {
    @include some-component-a();
}

output.css

html[brand=a] .some-component {
  display: inline;
}
html[brand=a] body[lang=fr] .some-component div {
  display: flex;
}

html[brand=a] .some-component div {
  display: block;
}
html[brand=a] .some-component__span {
  display: inline-block;
}

settings.json

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