Bash completion for git aliases containing nested subcommands

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