It depends. 😃
But seriously, it does. It depends on the piece, and the player, and how easy/difficult the piece is for the player and where the player is at at that point in time.
For me, recently I've worked on a few pieces that are decidedly "under" my playing level, and one that is above (or maybe just barely above, hopefully) my playing level.
For one of the easy pieces, it's four pages long. I was able to sightread it through to the end on first try. So I quickly chucked it up into 4 sections, looked for any spots that might trip me up (and found them, they were transition spots), and made a note for myself to practice as follows: 1) practice those spots in isolation; 2) make sure I have each section down; 3) play the whole thing through. And now I'm working on dynamics and musicality with this piece.
For the piece that's just a little too hard, I am taking a totally different approach. It's five pages long and I couldn't really get past page two on the first sightread through. So after that initial go, I stepped back and chunked up the first page (through to line one of page two) and made practice sections for myself. Then the first thing I did was writing in fingerings. Unlike the piece I mentioned above, where I wrote in a few fingerings here and there, in this piece, I have been writing in multiple fingering notes in each measure. And it's taking me a long time. I've been working on this piece for about a week now and I've only fingered up through the top of page two.
In terms of practicing, I'm practicing those chunks in 4- or 8-measure chunks, working on the notes, the rhythm, the tricky timing etc. I'm not at tempo yet and I'm not focusing on dynamics yet because I'm still working on getting the notes in my fingers. And I'm not allowing myself to go past the top of page 2 (although I will this weekend, I think it's starting to come together now).
I should also say, I've actually played this piece before and it was too hard so I got it to a certain point and put it aside. That was 3 years ago I think. It's still hard but I feel like I'm ready to work on it now, but it still feels like I'm learning it for the first time.
So hopefully these two descriptions are somewhat helpful in fleshing out what "it depends" means...