nested-extend.scss

%place1{
    font-size: 12px;
}

%place2{
  @extend %place1;
  color: blue;
}

%place3{
  @extend %place2;
  color: red;
  border: 1px solid red;
}

%place4{
  @extend %place3;
  color: green;
  border: 3px solid green;
}

.style{
    font-size: 14px;
}
.style{
   @extend %place4;
}
.style2{
    @extend .style;
    background: red;
}