On my Nikon D5300, i saw a dust spot I clean the sensor and mirror. It did not go away?

On my Nikon D5300, i saw a dust spot I clean the sensor and mirror. It did not go away?

Added (1). I had a better look. I found that dust speck is inside of camera. Inside side of the focus screen. How do I get this clean? I watched you tube videos of Nikon and canon cameras focus screen been replaced and clean. It looks simple enough. Should I do it or better to take it to a camera shop and let them do it. I KNOW this does not affect the image but its right in the middle of screen so huge distraction.
I'm an electronic engineer so i do work with very fragile circuits and steady hands

Okay.

Is the dust on the focusing screen? If so, if is bugging you too much, have it removed by a competent camera repair shop

Is it the mirror? If so, if you can't remove it by using a blower (like the Rocket). If it is still stuck, then you need to have it professionally removed. If you try, you will probably damage the front surfaced mirror

Is it on the sensor? Then you need to activate the dust removal feature of the camera. If the dust is actually sticky like pollen, then it needs to be removed professionally.

The bottom line, you need to protect your camera from dust by keeping it in your camera bag when not in use. When you change lenses, you need to do so where there's no floating dust or any wind

You opening the camera to clean the focusing screen will void your cameras warranty