How to display categories, subcategories and products on one page by adapting Virtuemart modules?

Question

Joomla

There is an old site on the old joomla 1.5.23 with a product catalog on virtuemart 1.9, from the SEOs the task was to display the catalog in this way:

• First level category (h1 heading)
  
  • Second level category (h2 heading)
    
    • Third level category (h3 heading)
      
      • product
        
      • product
        
      • product
        
      • product
        
      
      
    
    
  
  

Is it possible to somehow adapt existing virtuemart modules for this task with little effort? Tell me what, or another way to solve it, except to move to another CMS? =)