Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.6)
// Compass (v1.0.1)
// ----

$debug: null !default;

.foo, .bar, .doh {
    // get-context() => ".foo, .bar, .doh" 
   &.active {
   // get-context() =>  ".foo.active, .bar.active, doh.active"
   }
   &.active:hover {
   // get-context() => ".foo.active:hover, .bar.active:hover, doh.active:hover"
       span { 
         $debug: & !global;
       // get-context() => ".foo.active:hover, .bar.active:hover, doh.active:hover", "span"
       }
   }
}

body:before {
  content: '#{$debug}';
}

SassMeister-output.css

body:before {
  content: ".foo.active:hover span, .bar.active:hover span, .doh.active:hover span";
}