It is possible to do, but you will have to change "Dropdown links" on "Link blocks". Because, unfortunately, it is impossible to put anything inside the "Dropdown link"
So when you have a Link block (you can give it same class, it will be styled exactly as you have it now)
1) you can put "Tooltip div" inside that block
2) Link block will have position: relative and Tooltip div - position:absolute
3) by using absolute positioning you move Tooltip div on the position that you want and give it z-index higher than all menu links
4) make Tooltip div display: none and opacity:0%
5) Create interaction for Link block ("dropdown link") with Hover trigger:
- trigger = Hover, affect different element = Tooltip div, Limit to nested element
- hover over: 1step = display:block, 2step = opacity:100%
-hover out: 1step = opacity:0%, 2step = display: none
6) Connect this interaction to every menu link or duplicate created link (with interaction and tooltip)+change content
Hope it helps.