This is a feature that has been requested many times. It will happen one day!
You could try copying all the music to the leadsheet, changing your filter to Deselect only, and then you will be able to gradually filter to deselect the notation that you don’t want to delete (what you want to keep) and delete what remains.
And so, you could just go:
Make sure Deselect only is activated
Filter > Top Note
Filter > Dynamics (assuming you want to keep them)
Filter > Slurs (if you want slurs)……. etc.
Delete
Everything that remained selected - everything you don’t want - should be deleted with only top notes, dynamics and slurs remaining.
You’d be able to do each of these via the Jump Bar too, with no right-clicking, and at the end, everything you don’twant in the leadsheet should be selected and then you can delete.
This process will be easier with the fewest notation-types you want to keep
Sometimes you can fake an additive filter by using Select More, but I don’t think it will work in this case. Once you have filtered for top notes, then Ctrl/Cmd+Shift+click a lyric and do Select More, you’ll get all of the lyrics added to your selection – but also all of the notes that you just filtered out.
Thank you all for affirming that I’m not nuts. To the Dorico developers: No new invention needed; check out the Edit Filter dialog in Finale Lots of checkboxes, but it worked!