Where can I find Filter coffee in Oberarth?

Filter coffee can also be found in these cities:

Altdorf Baar Buchrain Buochs Cham Ebikon Einsiedeln Emmen Goldau Horw Ibach SZ Ingenbohl Kriens Küssnacht Lucerne Richterswil Rotkreuz ZG Stans Steinhausen Unterägeri Urswil Wädenswil Zug

You can also find this in Oberarth:

Everything From Milk Baking Mixtures Cream Stiffener Spreads Savory Food For Diabetics Menus With Meat Fruit Spritzers Baguette Roll Salt Sticks