How to exclude some of the multiple selectors?

.component .branch-aThe selector you want to keep .elementThe element you want to style,
 .component .branch-b .element,
 .component .branch-c .elementThe selector you want to omit

SASS

+component('.component')
  +register
    +element('{blocks}', '.header', '.body', '.footer')

  +__________________________
  +element('{blocks}')
    +default
      display: inline-flex

    +only-for('.header')
      order: 1

    +only-for('.body')
      order: 2

    +only-for('.footer')
      order: 3

CSS

.component .header, .component .body, .component .footer {
  display: inline-flex;
}

.component .header {
  order: 1;
}
.component .body {
  order: 2;
}
.component .footer {
  order: 3;
}

More info: +only-for, +element, +register, +component, separator +___