This would be near-impossible to do across the entire site. But on each Pokedex above the move table you can click the numbers to view moves for a different generation. Then if you want to look at a different Pokemon one quick way to do it is replace the name in the URL.
For example if you were looking at Skarmory's Gen 3 learnset
You can easily switch to Nuzleaf by replacing
skarmory in the URL:
Hope that helps.