From Oslo...Norway in a Nutshell...Copenhagen?...Ideal itinerary??

I can definitely appreciate your situation, as there is so much beautiful scenery in Norway and never enough time to see it all.

I'm guessing from your last question (about Copenhagen) that your flight out isn't until 7:30 pm. If that's correct, I would suggest taking Norway in a Nutshell to Flåm, spend a night there, and then continuing to Bergen for 2 nights, and then fly back to Oslo from Bergen on Sunday. Alternatively, you could do Sognefjord in a Nutshell and spend the first night in Balestrand before continuing on to Bergen. And if you'd prefer to spend more time in fjord country, you could extend your stay in Flåm or Balestrand to 2 nights. You could still make it to Bergen by early Saturday afternoon and have half a day Saturday and some of Sunday morning to see Bergen before flying back to Oslo.

Flying to Copenhagen makes no sense in my opinion. Save that for another trip.

...and then continuing to Bergen for 2 nights, and then fly back to Oslo from Bergen on Sunday.

If you depart OSL Sunday at 7:30 you may want to fly from Bergen Saturday afternoon/evening and spend Saturday night in a hotel a shuttle drop from OSL.

In my opinion, Oslo is worth two full days of exploration and Bergen one full day. Start the Nutshell from Oslo S Thursday morning, overnight somewhere between Flam and Voss. Continue to Bergen Friday morning and overnight in Bergen Friday night. Depart Bergen by air Saturday afternoon/evening.

If you arrive Oslo late on Tuesday, consider departing Oslo S Friday morning to get two full days plus in Oslo. Spend Friday night in Voss taking an morning train to Bergen Saturday morning to get more of a full day in Bergen before an evening flight to OSL.

Rick's Oslo 3 and 2 star list: https://www.ricksteves.com/europe/norway/oslo

▲▲▲ City Hall Oslo's artsy 20th-century government building, lined with huge, vibrant, municipal-themed murals, best visited with included tour.
▲▲▲ National Gallery Norway's cultural and natural essence, captured on canvas.
▲▲▲ Frogner Park Sprawling park with works by Norway's greatest sculptor, Gustav Vigeland, and the studio where he created them (now a museum).
▲▲▲ Norwegian Folk Museum Norway condensed into 150 historic buildings in a large open-air park.
▲▲ Norwegian Resistance Museum Gripping look at Norway's tumultuous WWII experience.
▲▲ Viking Ship Museum An impressive trio of ninth-century Viking ships, with exhibits on the people who built them.
▲▲ Fram Museum Captivating exhibit on the Arctic exploration ship.
▲▲ Kon-Tiki Museum Adventures of primitive Kon-Tiki and Ra II ships built by Thor Heyerdahl.
▲▲ Holmenkollen Ski Jump and Ski Museum Dizzying vista and a schuss through skiing history.

Rick's Bergen: https://www.ricksteves.com/europe/norway/bergen

Bergen is permanently salted with robust cobbles and a rich
sea-trading heritage. Bergen still wears her rich maritime heritage
proudly — nowhere more scenically than the colorful wooden warehouses
that make up the picture-perfect Bryggen district along the harbor.
Enjoy Bergen's salty market, then stroll the easy-on-foot old quarter,
with cute lanes of delicate old wooden houses. From downtown Bergen, a
funicular zips you up a little mountain for a bird's-eye view of this
sailors' town. A short foray into the countryside takes you to a
variety of nearby experiences: a dramatic cable-car ride to a
mountaintop perch, a scenic stave church, and the home of Norway's
most beloved composer, Edvard Grieg.