IOS/Xcode/Assistant Editor: Is it possible to open two .m files simultaneously

In Xcode 11, if you open the supposedly "smart" Assistant Editor when looking at a .h file it automatically gives you the complement eg .m file.

They seem to have taken away the Manual option but you can still do CmD-Shift-O to bring up the Assistant Editor and then click on siblings to see a lot of other file chices. However, the file options don't have a .m option. If you choose any one you automatically get the .h file. You can pull up the .h file and the choose complement to make the . m file appear in the right pane. But then it automatically changes the left pane to the .h file of the file in the right pane.

So far, I haven't figured out a way to look at two .m files (for two different classes) simultaneously?

Does anyone know of a way to do this in Xcode 11?

Thanks in advance for any suggestions.

You could add an editor and then you will have two side by side editors with two different .m files as in the screenshot below.

The button you are looking for is far right in the screenshot (with the little + inside). Note that you need to use that button and not the assistant window.