Possible. See: https://www.norwaynutshell.com/original-norway-in-a-nutshell/flam/
(Note that it is possible to self-book each travel mode yourself and save a bit especially if you can book Minipris rail tickets). Just don't make a mistake and miss the boat.)
(I'm surprised that the cruise ship isn't pitching a excursion add-on package featuring this route).
The Norway in a nutshell® round trip from Flåm
Fjord cruise on the magnificent Aurlandsfjord and on the narrow
Nærøyfjord
Bus trip through beautiful scenery, including Stalheimskleiva
The scenic Bergen Railway
The breathtaking Flåm Railway
See schedule: http://assets.fjordtours.com/fjordtours-umbraco/5646/norway-in-a-nutshell-from-fla-m.pdf?_ga=1.185738089.1381581106.1489618804
Round trip from Flåm via Myrdal
Flåm-Myrdal-Voss-Gudvangen-Flåm
Depart 9:45
Return 17:30
or
Round trip from Flåm via Gudvangen
Flåm-Gudvangen-Voss-Myrdal-Flåm
Depart 10:00
Return 16:55 or 15:40