A living will states who will take care of your financial, medical and personal business when you are unable to do it yourself. It is a personal document that must be drawn up by a notary and will be filed in the Central Register of Living Wills (CLTR).
You can decide yourself who will take care of your business. It is common to appoint 2 persons: one for your financial matters and one for your medical and personal matters, but this is not compulsory. Whoever you choose, make sure it is someone you trust very much.
Your living will can’t expire but you can always change it.