You can quickly identify who the Ultimate Parent of a company is by clicking on the Group Tab on a Company Profile Page.
The Ultimate Parent will be the darkest coloured circle on the graphic. For more detailed descriptions you can look at the Ownership tab which will break down all of the parent and subsidiary companies within a group structure and their degree of separation. In the below example we can see a complex Group Structure for Spotify Limited. In this case, the darkest bubble is Spotify Technology S.A meaning this is the Ultimate Parent.
This is then also shown on the Ownership Tab as the Ultimate Parent for further clarity.