how to add multiple titles at the same frame in iMovie project

Question

I created a new movie in iMovie (version 10.2.5) in Mac OS.

I can easily add titles consecutively and other items. I can also add effects and customize it without any issue.

I want to add multiple titles for a frame that can animate separately in a new row (not in row1, row2 or row3 as shown at the image below).

I tried to illustrate what I want to do, in image below;

Currently row1, row2 and row2 exist in my project. When I drag an another (new) title it forces to place the titlebox in Row1 (or at the end or beginning of Row2) wherever I drag it. I want to be able to create a new row (like adobe flash timeline editor, that were very popular long time ago)

Is it possible to add a new row(s) for other items, like "sample" and "sample2", shown in the image, especially to be able to manage each's animation separately?

Thank you