I don't know how, as generally I have a dislike for Melia based on multiple experiences with their customer support, but recently I have achieved MeliaRewards Platinum status!
There is a handy counter in the app (but not that I can see on the website) which showed me how many more nights/stays/spend I needed to qualify for Platinum. Now that I've reached platinum this counter has dropped down to 0 (e.g. 0 nights required to qualify for Platinum). Does anyone know if this will change soon so that it will help me track how well I'm going towards maintaining my status? As there are certain quirks to the program I only noticed with the aid of this counter i.e. multiple room bookings under separate reservations in the same name did count towards these nights; or that the nights got recognised a few days after check-in for a relevant stay and not after check out.