A quick DuckDuckGo search tells me there's a Beolab 8000 (active speaker) and a Beosound 9000 (radio/CD sound center) but no Beosound 8000. Do you own the Beolab 8000?
If so, you can connect their RCA inputs to the line outputs of the WiiM Pro.
The WiiM Pro doesn't have a dedicated subwoofer output providing the filtering. Depending on the actual subwoofer you have in mind it might still be possible to connect it. The WiiM Ultra would be a better (yet more costly) fit.
The optical input (SPDIF in, available with the WiiM Pro and the WiiM Ultra) can be used to connect any TV that has an optical output. Additionally, the WiiM Ultra supports connecting a TV for sound reproduction over HDMI ARC.