I have a fairly similar opinion to @mambabasa, I have no real issue working with anyone on the left, even the more liberal types as long as our goals happen to be aligned.
The only 'left' group I would not be able to work alongside in good conscious, are tankies. Every time in recorded history that Anarchists have teamed up with authoritarian leftists, it inevitably went south in some of the worst ways possible.
I've never met a tankie in real life, only ever encountering them online, but if I ever did meet one, that would be my line in the sand (at least, if anything meaningful was on the line). There's no need to repeat that part of history again.