How to loop through a nested array in liquid syntax

Help
1

I am accessing the data from a json file from _data folder, I have this json data

{ 
   "content":[ 
      [ 
         "Unit I - Basic Principles of Electricity",
         "Introduction to basic principles of electricity - Classifications of materials - Basic "
      ],
      [ 
         "Unit II - Work, Power and Energy",
         "Work - Force - SI unit - Problem. Power, Energy - Electrical power - Electrical energy - "
      ]
   ]
}

An array holding two array’s withn the two array I have two array items. I try looping Like this And I dont get any output

{% for parentArr in page.content %} 

 {% for nestedArr in parentArr %} 
  {{nestedArr[0]}}
 {% endfor %} 

{% endfor %}

Also I am using jekyll-datapage_gen plugin to create pages based on the json data in the _data folder. I would also like to add than I can access other values like page.title and page.objectives etc.