Bash completion for git aliases containing nested subcommands

["Tim Jaacks" <timjaacks@posteo.de>]

Hello everyone,

I have set up the following alias in my .gitconfig file:

[alias]
     ss = stash show

Unfortunately bash completion does not work correctly on this alias. 
When I type "git ss <TAB>", I get:

$ git ss <TAB>
apply clear drop pop show
branch create list push

Which is obviously the completion for "git stash" instead of "git stash 
show".

With the original command I get the list of available stashes:

$ git stash show <TAB>
stash@{0} stash@{1}

Is there a way to get the completion on the alias behave like on the 
original command?

I am on Ubuntu 20.04 and using the distro's default git completions.

Kind regards,
Tim