Quoting Wikipedia:
The simplest case is when $Γ$ is cocompact, when the representation breaks up into discrete summands. Here the trace formula is an extension of the Frobenius formula for the character of an induced representation of finite groups.
How do I understand this sentence? For me it seems that they are not really related. Does it mean that we can deduce Frobenius formula from the Selberg trace formula? If so, how?