Less allows the usage of the  parent selector (&) anywhere in a complex selector and thus allows changing styles when the current element is within another element which gives it a different context:
For example, in the below code the parent selector is placed at the end and thus it actually becomes the child's selector in the compiled CSS.
a {
  color: blue;
  .disabled-section & {
    color: grey;
  }
}
Compiled CSS:
a {
  color: blue;
}
.disabled-section a {
  color: grey;
}