bud-- writes:

ONLY IF YOU KNOW WHAT YOU ARE DOING - you could take a neutral from an
A-leg circuit and a neutral from a B-leg circuit, wirenut them together
with a single wire to the neutral bar. It is easy to do this wrong.

Can't you also combine two A-leg neutrals, as long as the pigtail
between the wire nut and the neutral bus is sized to carry the sum of
the two circuit currents?

Dave