UNECE has a very good map of European waterways available here: https://unece.org/DAM/trans/main/sc3/AGN_map_2018.pdf
Here you can see that there are quite a few options. The route north to the Netherlands has already been mentioned, but you can also go south to France, and then across to the Rhine.
Yes, from Brugge you can follow the Boudewijnkanaal to Zeebrugge, then turn North to where the Merwede and Rhine reach the North Sea.
Granted, this is not exclusively a canal/river trip, so your boat needs to be seaworthy.
According to Eurocanals site, the answer is yes. One possible route is: Brugge – Gent – Antwerpen – Dordrecht – Nijmegen – Düsseldorf. From there you can even join the Danube River and the Black Sea.
I found the following map (Source: http://www.yachtchartersneek.nl/waterkaart_Belgie_vaarwegen.htm)
The map is from a charter company, which have suggested routes on their website. One mentions a connection from Bruges to Ghent.
From Ghent on there a multiple possibilities.
Credit:stackoverflow.com‘