Create View That Overlays The Theme When Field Clicked
You can achieve this effect like this for example:


You put a view block on top (which will overlay the other content) and put the other content below, position them on top of each other with position: absolute.
Then create a button and position it however you prefer.
Use jQuery .click() with this button (http://api.jquery.com/click/) to hide and show your view block. One possible solution is that on click, you examine if the view block has a "hidden" CSS class (for example). If it has "hidden" on click, you remove the class with .removeClass("hidden"), if it doesn't have the class, you add it with .addClass("hidden").
CSS styling should be like this: .hidden{ display: none; }