How to swap the note section to the left side when using a Split View?

First of all, you may go to read a document from the Library. And then tap the "Text Notes" icon on the floating toolbar. 

Then, please follow the steps below to swap the note section to the left side.

Step 1. Tap the hidden menu icon framed in red as below. 

Step 2. Tap "More", and select "Swap".

Now, the note section is swapped to the left side.