Using Centos.

I'm logged in as user bob. How do I configure tab completion with sudo
to access user tom's files, or roots.

Thanks!

It depends on your PATH variable.

For temporary add use export.
For permanent edit .bashrc

I'd rather use su imho...

Could you elaborate?
Unfortunately su is not an option

This is the contents of /etc/sudoers

bob ALL=(ALL:ALL) NOPASSWD: ALL, !/bin/su

That tab completion is being performed by your current shell, which might not even have read access to other users' home directories. Without that, there's no way it could do tab completion for file names there. Even with read access, it's asking a lot to expect the shell to know ahead of time what the CWD will be when that command runs and expand the names of files that are there. It's like typingand expecting that to expand to "messages". Sorry, but the shell is working in the here and now, not in some future environment.

That said, you can do a lot of tricky things in /etc/bash_completion.d, but setting that up to do anything like what you are asking is a bit beyond my pay grade.

To have autocomplete, add what you want to be autocompleted to your path.

Type the command then go to beginning of the line and add sudo