"What are you doing in your life?" sounds a bit unusual to me but if I heardf it I would take it to mean "What is going on in your life?" or "What have you been doing these days?" However, we have a much more common question of this type, "What are you doing WITH your life?" which asks the question ''What are you accomplishing?" or ''How are you using your abilities to achieve success?" It is generally asked of those who seem to be squandering their talents.