less.js/test/less/selectors.less

h1, h2, h3 {
  a, p {
    &:hover {
      color: red;
    }
  }
}

#all { color: blue; }
#the { color: blue; }
#same { color: blue; }

ul, li, div, q, blockquote, textarea {
  margin: 0;
}

td {
  margin: 0;
  padding: 0;
}

td, input {
  line-height: 1em;
}

a {
  color: red;

  &:hover { color: blue; }

  div & { color: green; }

  p & span { color: yellow; }
}

.foo {
  .bar, .baz {
    & .qux {
      display: block;
    }
    .qux & {
      display: inline;
    }
    .qux & .biz {
      display: none;
    }
  }
}