Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.3)
// Compass (v1.0.0.alpha.18)
// ----

.foo, .bar {
  &__element {
    color: blue;
    &--modifier {
      color: red;
    }
  }
}
.baz {
  position: relative;
  width: 50%;
  &__element {
    color: red;
    &--modifier {
      color: blue;
      text-decoration: underline;
    }
  }
}

SassMeister-output.css

.foo__element, .bar__element {
  color: blue;
}
.foo__element--modifier, .bar__element--modifier {
  color: red;
}

.baz {
  position: relative;
  width: 50%;
}
.baz__element {
  color: red;
}
.baz__element--modifier {
  color: blue;
  text-decoration: underline;
}