How to go up a level in sass?

Question

Sass

There is a style structure like this:

.block {
  &__text {
    ...
  }

  &__title {
    ...
  }
}

But for the block I want to have a modifier that affects children:

.block {

  &--open {
    .block--text {
     ...
    }
  }

  &__text {
    ...
  }

  &__title {
    ...
  }
}

How can I go up a level above &--open and not write the entire selector ?

Answer 1

The variable $this.
A typical problem when creating self-controlled components (especially when using the BEM methodology) is creating selectors inside modifiers.
Instead of:

.filter-block {
    &__title {
        color: black;
    }
        
    &--expandable {
        .filter-block__title {
            color: blue;
        }
    }
}

Can:

.filter-block {
    $this: &;
    &__title {
        color: black;
    }
    &--expandable {
        #{$this}__title {
            color: blue;
        }
    }
}