Concat downloaded content by wget
This is very hard to read like that.
The duplication of the same base url is also not great.

With the -O flag, you could specify - to make the output go to stdout.

Lastly, `...` is obsolete syntax, use the modern $(...) instead.

baseurl=https://chromedriver.storage.googleapis.com
filename=chromedriver_linux64.zip

version=$(wget "$baseurl"/LATEST_RELEASE -O-)
wget "$baseurl/$version/$filename" -O "/tmp/$filename"