No no, I know, you would need 2 units, but they could be housed in the same case.
Usually, you need a separate TX/RX antennae, with enough physical separation to keep them from interfering, assuming standard
Cross band eliminates the interference so long as you didn't pick a harmonic and allows you to mount the antennae near to each other.
And they can be ad hoc, not worrying about having a repeater frequency license. (Totally full where I am)
No idea if TDMA solves any of the issues above with cross band, probably need to read about it more.