I've written about qualification requirements for holding elected or appointed office before, and one concern often raised is how they could be politicized/weaponized against already marginalized folks.
One very simple requirement that shouldn't be subject to this problem though, is that to hold office at level N+1, you must have been reelected in a position at level N.
I.e. folks were happy enough with your work at lower level to keep you at least once.