To create a portfolio as a drop-down menu with a double nesting level:
Portfolio (drop-down menu)
Love Stories (Album Gallery)
— Helen and George (album)
— Bernard and Cathleen (album)
— Isabel and John (album)
— …
Family (album gallery)
— Family traditions (album)
— William and Elizabeth (album)
— Family meeting (album)
— …
Weddings (album gallery)
— Jean and Daniel (album)
— Chloe and Christopher (album)
— Grace and Robert (album)
— …
…
Go to the Site section and follow these steps:
Click on the Add to site button and select the Drop-down menu item.
Enter the name of the main section (e.g., Portfolio), which will contain nested galleries and click Add.
Add the first page to this dropdown menu — click on the Create new button, select the page type and name it (e.g., Love Stories).
Click on the + Add button, enter a name for the album and upload your photos.
This way, you have created a drop-down menu, and a gallery of albums in it. To add another gallery of albums, go to the previously created drop-down menu (Portfolio) and click on the Gallery item again.
You can change the albums and galleries view in the Design section.