The local transportation in all of Flanders - the Flemish (Dutch) speaking part of Belgium is provided by de Lijn https://www.delijn.be/en/
Day tickets or 10-trip cards are valid on all their services throughout all of the covered area, and they do have a few buses which go into Brussels (which would be covered but there aren't many). So you can use a de Lijn pass or 10-er in Brugge/Bruges (D/F&E), Gent/Gand/Ghent (D/F/E), Oostende (D) and on the Coast Tram all the way down to Plopsaland, and in Antwerpen/Antwerp (D/E) and points in between. De Lijn tickets of any sort are only usable on their buses and trams, not on trains.
More information from their English language tickets page https://www.delijn.be/en/vervoerbewijzen/ritkaarten-dagpassen/
If you want everything in Brussels you need the intra-company Jump card https://www.delijn.be/en/vervoerbewijzen/ritkaarten-dagpassen/jump.html Most transportation within Brussel/Bruxelles/Brussels (D/F/E) is provided by STIB/MIVB (D/F).
I've put in the various languages because you will see a lot of that, and in Flanders everything will be in Dutch before French and English, in Wallonie/Wallonia (F/E) everything will be in French alone or French and then Dutch and/or English, and in Brussels it will be almost always in French and perhaps then and/or Dutch or English.