UI for multiclass classification taxonomies and search results

I am confused about how to present multiclass classification taxonomies to the end user on a consumer app. If an item or even an entire subcategory can be classified under different parent categories, what's the simplest way to presenting that to the user.

For example, suppose I have -

  • how things work > home gadgets > refrigerators > how refrigerators work > articles 1-n
  • home gadgets > how things work > refrigerators > how refrigerators work > articles 1-n
  • home gadgets > product reviews > reviews of various refrigerators > articles 1-n

My question has two parts -

  1. What could be a good UI approach to presenting this?
  2. How does this mesh with search? Suppose someone searches for "refrigerator". What should my search results include? Just the actual articles? Or should I also indicate the different subcategories?

I am still formulating thoughts on the question, so if it can be improved please feel free to comment/suggest edits.