Opening custom post type ACF Gallery field in a popup with AJAX

The situation is this one:
I have a custom post type that I'm using for generating galleries with an ACF pro Gallery Field.
Then i have a shortcode that I use to list all the "galleries" on a custom taxonomy I've created for that matter. You can see what I'm talking about here:

those are the "featured images" from my Custom Post Type being called with the aforementioned shortcode.

If you click on the "thumbs" you'll be taken to the post showing the gallery field being rendered in a flexslider.

Untill here everything is nice.

Now, what i need a clue for, is:

How can I make those "flexsliders" apear on a popup with AJAX so I can see each "gallery" without leaving the thumbs page?

Like this:

Thanks in advance.

( I've granted also support access)