See my post #5 above, give it a read. In the pic you'll see 8 little white squares to the bottom left, well when you're not in split screen that location will show a larger square and 3 lines to the right of the square. Push that icon and you will switch to split screen, push the 8 squares and you'll go back. See easy peezy lemon squeezy!

 

CarPlay does this. I can see the map/nav on the left half, and the right half has up to three stacked windows, music, calendar,, etc..

 

I recently (Nov 2024) bought a 2025 NX450h+ plug-in hybrid. It does NOT have a split screen! This is totally daft -- the display is huge and there is more than enough space for two windows side by side. You can get a split screen with Android Auto (and presumably Apple Carplay) but NOT with the regular Lexus function display. This was a very big disappointment to me. I'd previously been driving a Prius Prime PHEV and it had a very well designed split screen system. You could have the map on one half of the screen, and a choice of many other functions (including none) on the other half. I liked to keep the audio controls on one half so I could see the song titles from the radio, while I could continue to see the navigation map. No such luck on the Lexus -- you can see the map, or you can see the radio, never both (or anything else) at the same time. It's incomprehensible to me why a Lexus that costs twice as much has a less useful display than a Toyota. My recommendation is that Lexus borrow some of the Toyota design team to work on their driver interfaces -- I've always found my Toyota's to be very well thought-out multimedia designs (I've had several).