In this passage I’d like to place the hairpins in the top part either above the staff or between the staff and the slur to save vertical space.
In the properties panel I’ve tried setting the hairpins to display above the staff but this shifts everything around it, including the dynamics, not only for this staff but for the one below it.
I’ve also tried using the contextual menu to unlink the hairpin, to ungroup it and to delete it from the group but none of this helps. What am I missing?
Have you gone into Engrave mode, selected the two hairpins under the top stave and nudged them up above the slur?
Yes. The hairpins in the bottom staff kept moving, as well, regardless of the dynamics settings for linking or grouping.
You’ll have to unlink those dynamic groups in order to give them separate placements. In the fullness of time I expect this will change, and you’ll be able to specify placement and dx/dy changes to linked dynamics independently, but for now they’ll need to be unlinked.