By alternate, do you mean if the switch is up, then Input* A connects to Output 1 and Input B connects to Output 2, but if the switch is down, Input A connects to Output 2 and Input B connects to Output 1?
That’s pretty dead simple to do passively with 4 jacks and a DPDT switch (on-on, or if you want to disconnect everything in the middle position, on-off-on). You could add as many ‘output’ jacks as you wanted, but they wouldn’t be buffered. *Note, they’re not really ‘ins’ and ‘outs,’ they’re just connections. There’s nothing at all directional about this.
Apologies if you’re looking for buffered/more complex.