If a channel has a active cue send, it shows up in Ic pro. All 4 cue mixes are there, the interface gives a choice- you can look at either the cue mixes, or the channel faders, one or the other.
I copied this from the manual:
On the MixConsole page, you can control the most important
MixConsole parameters in your Steinberg DAW or control individual
cue mixes.
In Cubase iC Pro, you can access the cue mixes that you set up using
the Control Room in your Steinberg DAW. That way, the artists can
adjust the levels of their independent headphone mixes directly from the
recording room, while the main mix remains unaffected. The cue mixes
in Cubase iC Pro directly correspond to the four cue channels in your
Steinberg DAW.
NOTE
The cue mix function is directly linked to the Control Room. Therefore it
is only available in the full version of Cubase.