Is it possible to have PR + 2 branches being built?

I am trying to configure CircleCI to only build to PR commits + 2 branches.
It is similar to what we have now on “Only build pull requests”, which builds PR commits and default branch commits. The difference is that instead of 1 default branch where it always run, I would have 2 branches.

If possible, I would prefer not to run, instead of verifying that on bash, as my build is very complex right now.

Thanks.