Question about Bose Solo 5

At least via this soundbar, that's certainly not possible. It is an all-in-one soundbar. No connections for additional speakers. There is also no Bluetooth or anything else with which you could connect something wirelessly.

as far as i know, this is not possible.
it's just a soundbar that can be connected with an optical cable or a jack plug. i couldn't add this soundbar to the bose app at the time either.