The elements outlined in blue have the necessary attributes for this solution. Toggle X-ray by pressing ? on your keyboard and hover the outlined elements to reveal their attributes.

These attributes are only needed for the Example 01 - Default Nest items.

The elements outlined in blue have the necessary attributes for this solution. Toggle X-ray by pressing ? on your keyboard and hover the outlined elements to reveal their attributes.

These attributes are only needed for Example 03 - Multi Nested Collections.

Please check the 
Categories Template
for further steps on implementing this solution.