Loop unique values in nested data tree in Jekyll - jekyll

Question

I have a data files with different items. Each item have nested tasks. I am trying to loop the nested tasks and present each task by the task type.
YML DATA
- name: Outside
description: Description
tasks:
- type: Food
name: Eat it outside
status: working
- type: Drinks
name: Drink it outside
status: working
- name: Inside
description: Description
tasks:
- type: Food
name: Eat it inside
status: pending
- type: Drinks
name: Drink it inside
status: working
Liquid
{% for item in site.data.info %}
{% assign grouped-tasks-by-type = item.tasks | group_by: "type" %}
{% for task in grouped-tasks-by-type %}
<h2 class="task-type">{{ task.type }}</h2>
<ul>
{% for task in item.tasks %}
{% if task.status == 'working' %}
<li>{{ item.name }}: {{ task.name }}</li>
{% endif %}
{% endfor %}
</ul>
{% endfor %}
{% endfor %}
Expected result (HTML)
<h2 class="task-type">Food</h2>
<ul>
<li>Outside: Eat it outside<li>
</ul>
<h2 class="task-type">Drinks</h2>
<ul>
<li>Outside: Drink it outside<li>
<li>Inside: Drink it inside<li>
</ul>
However, I am getting a full blank result. Is this possible to do with group_by?

Answer 1

I hope my algorithm below serves you well. I was able to achieve your expect end result with the algorithm. I was unable to utilize the group_by in my solution. The sample code contains Liquid comment blocks to explain my thought process.
Testing
I used the minima git repo, with command jekyll s. I placed your YML data in a file with path _data/info.yml in my locally cloned minima git repo. I used post.html as the code sandbox.
You can print out the Liquid variables to the DOM by doing {{ all_food_types | json }} in the code.
Solution
{%- comment -%}
End Goal: Find all the food types for <h2>.
1. Use map: "tasks" to gather all the tasks into a single array.
This will cause the loss of Outside/Inside information for each task
2. Use map: "type" to create a list of food types ("Food", "Drinks")
3. Use uniq to remove duplicate food types from the array
{%- endcomment -%}
{% assign all_food_types = site.data.info | map: "tasks" | map: "type" | uniq %}
{%- comment -%}
End Goal: Loop through all the data looking
for a specific food type (Food, Drinks)
and group them together
{%- endcomment -%}
{% for food_type in all_food_types %}
<h2 class="task-type">{{ food_type }}</h2>
<ul>
{% for item in site.data.info %}
{% for task in item.tasks %}
{% if task.status == 'working' and task.type == food_type %}
<li>{{ item.name }}: {{ task.name }}</li>
{% endif %}
{% endfor %}
{% endfor %}
</ul>
{% endfor %}
An aside, for whatever reason, my liquid ends up using a lot of arrays and for-loops.