I'm not sure I understand your question, but for your information, this device is NOT a speaker. It is only a Bluetooth receiver that can be connected to a speaker via the audio cable.
I assume you know that.
If the speakers you are using have two audio-in ports, you can connect both and either the speakers will automatically switch between your PC and the receiver or you will have to do this manually.
If your speaker only has one plug, you could buy a splitter so you can connect both at the same time.
If you also want to connect your PC via Bluetooth, it's even easier. Just connect and if you want to listen to music with your smartphone, just connect your smartphone.