@lpil the way I do this for my own snippets is to invent my own file types for libraries and then have a project local vimrc that sets those filetypes.
For example, if I have a ruby project using the rspec library my project-local vimrc might contain something like
augroup ExtraTypes
autocmd!
autocmd BufNewFile,BufRead *_spec.rb set ft+=.rspec
augroup end
Then I can keep my rspec.snippets separate from my ruby.snippets.
I realise your problem is a little different... I'm not sure of a good way to deal with this when using communal snippets repositories, but maybe a similar idea could be helpful?