Head over to the releases page and download the binary best suited to your operating system. Then, you'll need to eval the command that prints out the source code relevant to your shell.

What I mean is...

Add to your .bashrc or .bash_profile

eval "$(/path/to/bosh-complete bash-source)"

Add to your zshrc or .zprofile

eval "$(/path/to/bosh-complete zsh-source)"

/path/to/bosh-complete should be replaced with the location where you have installed the bosh-complete binary.

First, make sure that you're logged into bosh on the target you're trying to have it complete for - this tool reads your .bosh/config to determine auth information to use. If that's out of date, then bosh-complete can't auth any better than the bosh cli can (which is to say it cannot).

Also, be aware that completing some info is reliant upon you having already provided the flag for some other piece of information. For example, the --deployment flag can not be completed if the --environment flag has not been given yet, because bosh-complete has no way of knowing at that point which bosh director to query for deployment names!

Beyond that? I don't know! Maybe the thing you want completed isn't implemented (yet). Maybe there's a bug (gasp!). Drop an issue on the repository and maybe we can get through this together.