So by default, PB doesn’t have ‘segments’, it has one pattern for all the pixels.
That said, there is both a multi-pattern pattern you can use to do the above, as well as the ‘multi-map’ approach I wrote.
You mught want to flesh this out, maybe post a diagram of what you want to do. Lots of ways to do it: 3 separate strips with 3 ‘segments’ each, 1 long strip with 3 segments, or with 9 segments…
Power injection will be needed, as well.
Happy to help you figure it out, but to be clear, the above is non-trivial, so expect to learn how it all works, and to port whatever patterns you like into your own custom pattern.