I use a Thinktank Speed Racer, and have since about 2009. It is a largish waist bag that holds a gripped camera and three lenses. I have used it since I was shooting a D300, always with a wide, normal and long zoom.
Currently I'm putting a Z9, 14-30, 24-70f2.8 and 100-400 in it. I can't quite zip the top shot with the 100-400, but I may be able to rejigger things a bit so it fits. A 70-200 always fit, through I used an 80-400 instead for years. I did have to put the longest lens in the center, mounted on the camera for all three zooms to fit, and it's tight.
Here is a pic;

Thinktank Speed Racer. D300, 12-24, 24-70, 80-400, Water bottle holder and pocket on right are accessory add-ons.
Unfortunately, Thinktank no longer sells these. Seems a shame - I love mine. Besides keeping both hands free and the weight off my shoulder, I can work out of it standing up. I simply swing it to the front. I can also sit without taking it off, and work out of it then - useful in a helicopter. Also useful for riding on busses.
I originally picked a bag like this to a) put the weight on my waist instead of shoulder, and b) limit the amount of gear I could pack to one camera, three lenses. That has worked for me since 2009. That bag has a lot of miles on it. I'm surprised they quit selling them.
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Phoenix Arizona Craig
www.cjcphoto.net
"I miss the days when I was nostalgic."