When i have been to Flam there have been excursions to Gudvanger at the head of Nearoyfjord with a boat trip back to Flam. The excursion works both ways, coach to Gudvangen and boat back or vice versa.
On my first Flam call we had an all day excursion up to Myrdal on the railway, we broke down and were late but they delayed the Oslo Bergen express for us. Then on to Voss for a nice lunch by the lake. Then on to a coach to visit waterfalls and finally the spectacular Stalheim hotel for pastries and tea/coffee