Avenue: Add sub-menus to main navigation?

Hello! Apologies in advance for my lack of knowledge here. 

I'm on the Avenue template. I'd like to add folders/drop-down menus to my main navigation menu to reduce the number of indexed pages. This website is a great example of what I'd rather have: a main home/landing page with art, then a drop-down for different portfolios. I believe that website is the Harris template. 

My main navigation is currently structured like this and it's too cluttered:

If I try to add a folder to create sub-menus, I don't have the option to create an indexed page. I've tried a gallery, but it doesn't display more than one image at a time, and I don't think that's what I want.

Is there a way to achieve the sub-menus/folders how I want from the main navigation with the Avenue template? I'm open to changing my template if this is a limitation...I just suspect the limitation is my knowledge of how to do it! 😉 

Thank you so much! Please let me know if there's more info I can provide.

The only way is add a Folder then you can add link items to folder

Take a look at my Avenue site and see if my drop-down folders are close to what you want. 

my random views

3 hours ago, derricksrandomviews said:

Take a look at my Avenue site and see if my drop-down folders are close to what you want. 

my random views

Almost! I like how your Photography Lessons menus are organized, I would just like each of my portfolios to be organized like each of my indexed pages on my site...I'd just like them to be accessed via drop-down menus. The auto-columns instead of the basic grid are what I'd like, but I'm not sure if it's possible on Avenue or any other template. 

Thank you so much - you've helped me before! 🙂

I am not sure exactly what you want to do but I do have some suggestions. All your portfolio pages which I think are gallery pages can be added to a drop-down folder on the main nav bar like my photo lessons. Each of my lessons is a blog post and in addition, I created a post with a summary block that pulls content from the blog page filtered by the category "lesson" which I gave to each lesson post. That summary block post is the ALL LESSONS link in the pull-down menu. Avenue summary blocks also pull content from gallery pages. 

My questions are, if you want all your homepage work to be accessible from a drop-down menu, what will be your home page? What would it look like? Would you have one piece of artwork? Would you want a rotating image? How many links would be in your drop-down?  Maybe you could consider using a landing page, which I have done, to introduce your work, and have links to your drop-down menus on that page or to a page with the menus there, which could be in an accordion folder instead of being on the main nav bar. 

I am willing to help with this if you wish. 

Derrick