Is there a Bluetooth Standard or feature I can look for, that indicates that a product can have 2 or more devices connected to it at once, and smart switch between them? I then presume that not only that device needs it, but the devices connecting to it must support said standard or feature?

I want to try and find a WiFi and Bluetooth speaker, that I can connect my Echo Spot and 4K Firestick to, which doesn't require me to manually disconnect/reconnect/pair each time I want to use one or the other? The Spot use is as a speaker so I can use it as an alarm, and the Firestick to use said speaker as an external speaker, but I don't want it that if I use it at night to watch TV, that it won't work with the Spot the following morning because I forgot to switch it over. 

Perhaps that isn't possible, but in case we have any Bluetooth experts here, I thought I'd ask.