Hobby beekeeper here... Filtering just means it's passed through a mesh filter to extract just the liquid honey leaving any bits of wax or bee parts behind. It will still be full of local pollen. Any liquid honey you see in a jar had been filtered this way. Sometimes people heat the honey for extracting to make it less viscous and easier to process. Under 100F usually not considered a big deal. Over that and you're driving off aromatics that make that variety of honey unique. So raw, unpasteurized honey is the most healthy and delicious and makes the best mead. Older mead making recipes called for boiling the honey with water. Modern techniques simply mix the honey with cold water until dissolved. Sounds like what your local beekeeper is selling is the good stuff.