Replace focus on content button to New Experience / Modern Document Library

[Adrienne Kidd]

New document library view does not have focus on content button on top right hand corner. Can you please replace that?  Especially where the new UI takes up more space on the screen, we need to be able to hide the side navigation to focus on content.

[#2]

Ability to add customizations to new UI is coming and I think you will be able to do what you are asking for

[#3]

Is there already any solution to this request?

Though the topic is old, I couldn't find an equivalent feature for the "Focus on Content" button on Modern pages.
There is also an open request in UserVoice regarding this feature:

https://sharepoint.uservoice.com/forums/329214-sites-and-collaboration/suggestions/36731116--focus-o...