Return the Zoom Slider to Google Maps
Some time ago Google replaced the old zoom slider in Maps with plus and minus buttons. The good news is, if you miss this slider, it’s easy to get it back.
In Google Maps, just hover your mouse over the plus or minus buttons for a couple of extra seconds and you’ll be able to show the slider again. Once you’ve done that, you should stick with the settings each time to visit Maps in the future.
Show zoom slider on Google Maps | Google operating system