title: Converting a 2D range into a 1D array with spaces in Google Sheets
body: <p>I would like to convert a range/array like this</p>
  <pre><code>| Fruit     | Strawberry |
  | Fruit     | Blueberry  |
  | Fruit     | Banana     |
  | Vegetable | Lettuce    |
  | Vegetable | Cucumber   |
  | Vegetable | Carrot     |
  | Vegetable | Celery     |
  | Dairy     | Milk       |
  | Dairy     | Butter     |
  | Dairy     | Cheese     |
  </code></pre>
  <p>into a 1D array with spaces separating categories like this</p>
  <pre><code>| Fruit      |
  | Banana     |
  | Blueberry  |
  | Strawberry |
  |            |
  | Vegetable  |
  | Carrot     |
  | Celery     |
  | Cucumber   |
  | Lettuce    |
  |            |
  | Dairy      |
  | Butter     |
  | Cheese     |
  | Milk       |
  
  </code></pre>
  <p>in Google Sheets. I can easily achieve a 1D array without spaces with <code>=UNIQUE(FLATTEN(A2:B11))</code>
  where <code>A2:B11</code> is the original data range; however, I am not able to get the desired spaces separating categories.</p>
  <p>Could anyone help?</p>
  <p>Here's the example sheet: <a href="https://docs.google.com/spreadsheets/d/1ww1fkDRBUsVx-pLDJ4Qo9VXlzAZDEyYoANRdRK7Yum4/edit?usp=sharing" rel="nofollow noreferrer">https://docs.google.com/spreadsheets/d/1ww1fkDRBUsVx-pLDJ4Qo9VXlzAZDEyYoANRdRK7Yum4/edit?usp=sharing</a></p>