Manipulate channel within tap without affecting source channel

[gnxsf]

Is it possible to manipulate a channel within tap so that my manipulation doesn't affect the source channel? For example, I'd like to create one channel with elements 0 and 1 from a list, and another channel with elements 0 and 2. Using map ahead of tap affects the source channel such that I no longer have access to element 2:

Channel.of(['A', 'B', 'C'])
.map { tuple(it[0], it[1]) }
.tap { chan1 }
.map { tuple(it[0], it[2]) }      // this doesn't work
.tap { chan2 }

Instead, I'd like to be able to manipulate the channel "within" tap so that it doesn't affect the source channel. Something like this:

Channel.of(['A', 'B', 'C'])
.tap { chan1 = map { tuple(it[0], it[1]) } }
.tap { chan2 = map { tuple(it[0], it[2]) } }

Any suggestions on how I can accomplish this?

[gnxsf]

Channel.of(['A', 'B', 'C'])
.multiMap {
    num1: tuple(it[0], it[1])
    num2: tuple(it[0], it[2])
}
.set { chan }

chan.num1.view()
chan.num2.view()