Page as subcategory in navbar

Hello! Thanks for reading my post, can you please help me. I tried the Search, I guess the keywords were just crappy.

I have a page : wisdom

I want the page listed in a category, like this :
Plus (category)
– Download (subcategory)
– Cards (subcategory)
– Wisdom (as subcategory?)

Can I put “wisdom” as a subcategory? Is there any plugin or code for this. Thanks