I want to continue a friendship with someone my boyfriend doesn't like
Is it important to you to continue this friendship?
I feel that it'll be nice to have one of my friend groups intact.
While it is upsetting to have a friend that your boyfriend doesn't like, it is okay to have it. Your boyfriend doesn't have to like all your friends because you could end up just depending on him if you needed his approval all the time.
I don't really care what my boyfriend wants. I need to have the friendship with my friend to be okay when we break up.
From what you say, it sounds like your relationship with your boyfriend is coming to an end.  That is sad news, but it's your decision to move on.  It is especially important for you to maintain your existing friendships, and know that they will generally last longer than romances.