addressA send to addressB1
addressB2 sent to addressC
and so is no connection between the two addresses of the wallet ?
This is technically "impossible". In that scenario, AddressB2 has no knowledge or ownership of the coins sent to AddressB1.
However, this is the sort of strategy that Bitcoin mixers attempt to use to hide the connections between bitcoin addresses. For instance, they receive "coinsA" to addressA... and then forward on the same amount (minus a fee) of different "coinsB" from addressB to attempt to break the chain of transactions that would link the addresses.
For normal people, you would have to do this:
addressA send to addressB1
addressB1 sent to addressB2
addressB2 sent to addressC
And then you end up with the links in the blockchain A->B1->B2->C... which isn't any different to A->B->C. It just costs extra time/money for the extra transaction