BEx Query Designer - Key Date Hierarchy Grey

Hello,

In one of my queries, I implemented a time-dependant hierarchy. I have no trouble modifying the Key Date, but my key-users can't. I guess It's an authorization problem, but I can't find the right manipulation to do (new authorization role for user or RSSM manipulation).

A previous thread was on this subject:

Hierarchy Key Date

But I don't know this apply to my case (since I can add a Key Date as a developer)

Thanks for your answers

sOnO