Generated by SassMeister.com.

SassMeister-input-HTML.haml

%a
  test1
%a
  test2
%a
  test3

SassMeister-input.scss

// ----
// Sass (v3.3.14)
// Compass (v1.0.0.rc.1)
// ----

/**
* Failed to make a weird horizontal list.
*/

@import "compass";

ul {
  @include inline-list;
}

li {
  @include border-radius(10px);
  
  background: green;
  position: relative;
  border: 1px solid blue;
  padding: 0 20px;
  margin: 0;
  z-index: 10;
  & ~ &:after {
    @include border-radius(10px);
    background: yellow;
    content: " ";
    width: 100%;
    height: 100%;
    position: absolute;
    left: -90%;
  }
}

a {
  @include border-radius(10px);
  
  float: right;
  background: green;
  // display: inline-block;
  position: relative;
  border: 1px solid blue;
  padding: 0 20px;
  margin: 0;

  & ~ &:after {
    @include border-radius(10px);
    background: yellow;
    content: "a";
    width: 100%;
    height: 100%;
    position: absolute;
    top: -10px;
    // left: -90%;
  }
}

SassMeister-output.css

/**
* Failed to make a weird horizontal list.
*/
ul {
  list-style-type: none;
}
ul, ul li {
  margin: 0;
  padding: 0;
  display: inline;
}

li {
  -moz-border-radius: 10px;
  -webkit-border-radius: 10px;
  border-radius: 10px;
  background: green;
  position: relative;
  border: 1px solid blue;
  padding: 0 20px;
  margin: 0;
  z-index: 10;
}
li ~ li:after {
  -moz-border-radius: 10px;
  -webkit-border-radius: 10px;
  border-radius: 10px;
  background: yellow;
  content: " ";
  width: 100%;
  height: 100%;
  position: absolute;
  left: -90%;
}

a {
  -moz-border-radius: 10px;
  -webkit-border-radius: 10px;
  border-radius: 10px;
  float: right;
  background: green;
  position: relative;
  border: 1px solid blue;
  padding: 0 20px;
  margin: 0;
}
a ~ a:after {
  -moz-border-radius: 10px;
  -webkit-border-radius: 10px;
  border-radius: 10px;
  background: yellow;
  content: "a";
  width: 100%;
  height: 100%;
  position: absolute;
  top: -10px;
}

SassMeister-rendered.html

<a>
  test1
</a>
<a>
  test2
</a>
<a>
  test3
</a>