OMG, comon people. The question he is laying down, is clear enough.
He is asking what will happen in the following scenario.
Characters: Obito with Kamui, Kakashi with Kamui and a third user of Kamui (lets call him Uchiha NB),
who has a different dimension than Obito/Kakashi.
We know if Obito teleports Kakashi into the dimension of Kamui, that Kakashi can return.
Because Kakashi shares the same eye and the same dimension.
Kakashi will use his Kamui on himself and be able to return to the real world again.
NOW THE QUESTION!

.
If Obito, teleports Uchiha NB inside Obito's Kamui dimension, is Uchiha NB able to get back to the real world? (because he has a different Kamui dimension, different eyes).
Tbh, I think all jutsus of Kamui share the same dimension and if they dont, than Uchiha NB, could teleport from Obito his Kamui, to his own Kamui and from his own Kamui, back to the real world.