Generated by SassMeister.com.

SassMeister-input-HTML.html

<p class="output">
  The output number is
</p>

SassMeister-input.scss

// ----
// libsass (v3.2.5)
// ----

/**
*
* Is there any way to fetch the last key and a specific key inside it?
*
**/
$map: (
  key-1: (
    first: true,
    number: 1,
  ),
  
  key-2: (
    first: false,
    number: 2,
  ),
);

// Map fetch function by Hugo Giraudel
@function map-fetch($map, $keys) {
  @each $key in $keys {
    $map: map-get($map, $key);
  }
  @return $map;
}

.output:after {
  content: '' + map-fetch($map, key-2 number);
}

SassMeister-output.css

/**
*
* Is there any way to fetch the last key and a specific key inside it?
*
**/
.output:after {
  content: "2";
}

SassMeister-rendered.html

<p class="output">
  The output number is
</p>