How to open multiple divs in one fancybox modal?

Question

fancyBox

There are two divs with their id's, for example:

<div id="div_1">Первый</div>
<div id="div_2">Второй</div>

It is necessary to open one modal window with these two divs by clicking on the link. These divs are in different places on the site, and there is no way to merge them into one div.

<a data-fancybox data-src="#div_1, #div_2" href="javascript:;">Open demo</a>

This works, but the divs start spawning.
In fact, these are two menus, one in the header, the other in the sidebar, in the mobile version I want to combine them into one menu in the modal window.