Bluetooth hub/re-broadcaster device - question/request for advice

I would like to get a device which would act as a Bluetooth hub. I want to connect multiple audio sources to it (phone, tablet, laptop) and also multiple speakers (a bunch of low cost Bluetooth speakers at home). I want the thing to handle just one stream at a time. So ideally, whatever is played on the source side (just a “merge” of all the source signals) should be broadcasted to all the speakers. The motivation is to stop playing a discotheque with my little soundbars/speakers and audio sources. It’s a bit annoying, so I guess we can do better…

The thing is, I cannot find any device like that. Apparently Bluetooth transceivers act exclusively either in RX xor TX mode, but never simultaneously. I do not care for reasons why that is the case (protocol, single chip, whatever), I would like to get pointers to technology which could do this for me.

Does such a thing even exist? And if yes, how’s it called?

Thanks for any constructive advice.

Disclaimer: I am an electrotech layman, apologies for naivete.

@FailForward it's very complicated.

I think streaming to multiple sinks is possible with more bandwidth but also reading from multiple sources... You'll definitely have to modify stack to support that.