Isolate section of a spectrogram

I was watching this video and thought it would be nice if you could isolate part of a spectrogram in audacity.
You can do it the hard way with the equalizer, but I thought it would be nice if you could just click a button and isolate it just to listen to it real quick.

There are free plug-ins, which work in Audacity on Windows, where that is possible,
e.g. TDR Nova using the High & Low pass filters.

BTW that video is misleading: it has been simplified for purposes of demonstration.
The isolated sound heard is not what is being shown on the spectrogram on-screen.
In reality you would hear part of the birdsong with the crickets & with the tree-frogs.

I figured that he altered the audio, but I was thinking of something like the play button, except it just plays the selected part of the spectrogram.
Thank you anyways.