1<===> input.scss
2.parent-sel-value {
3  font-family: &;
4  .parent-sel-interpolation {
5    font-family: #{&};
6     .parent-sel-value-concat {
7        font-family: "Current parent: " + &;
8     }
9  }
10}
11
12<===> output.css
13.parent-sel-value {
14  font-family: .parent-sel-value;
15}
16.parent-sel-value .parent-sel-interpolation {
17  font-family: .parent-sel-value .parent-sel-interpolation;
18}
19.parent-sel-value .parent-sel-interpolation .parent-sel-value-concat {
20  font-family: "Current parent: .parent-sel-value .parent-sel-interpolation .parent-sel-value-concat";
21}
22