They can be set up completely independently, on several constant combinators. Obviously you can request things and set a constant combinator to have the same signal. And it would be weird if you couldn't put two groups in the same interface if they have the same signals. Constant combinators can have the same signal in multiple slots as well.
I'm assuming groups will be added together, like in a constant combinator.
What I wonder about is how autotrash values will be handled now. The interface pictures showed only a single value for each request, so are autotrash values handled as separate logistic groups now instead? Since constant combinators can only have a output value for each signal.
And what happens if I couple my personal requests to a constant combinator and another player changes the constant combinators with the same group?