Connect thumbnails directly to a fullscreen gallery

Hi everyone,
I have a question, I need help. I state that i’m not an expert in the field.

Situation:
1 ) I have a page I called ” Portfolio” , with various thumbnails. Each of these is connected to a different page that contains its own collection of images (wedding , fashion, nature , etc.)
2 ) If you click on one of the mentioned thumbnails – for example “Wedding” – it opens the page with “Wedding” images’ collection, which appear as a sequence of other clickable thumbnails
3 ) Clicking on one of the thumbnails of the collection “Wedding”, opens the gallery fullscreen, which in my case is handled by the plugin Fullscreen Galleria.

What I would like to get:
I would like that clicking on one of the thumbs on my page “Portfolio”, it opens directly the fullscreeen gallery, without having to click on a thumb of the page that contains all the images in the collection that I want to display.
In summary, I would like to create a direct link between the single thumb on my “Portfolio” page, and the respective gallery fullscreeen.

To better explain:
Go to link http://joannedunn.it/wedding-photographers-ravello-amalfi-positano/weddings/ and click on one of the thumbs, this is precisely the result that I would get. (click on thumb -> opens directly the gallery fullscreen).

Thanks in advance for any advice or indication,
K.