Matteo
I am not clear what it is that you are trying to do. But let me make a suggestion. While there are 16 privilege levels (0 through 15) there are two levels that are commonly used 1 and 15. 1 is what is usually called user mode and is the default level when someone first logs into the router. My suggestion is to identify what group of commands you do not want to be available in user mode, decide if they should be available in something less than 15, pick a level, and assign the commands to that level.
If you really do want to start from a list of commands and their privilege level, I do not think that you will find any single source which will accurately give you the privilege level for all commands. The closest you will find is to look in the command reference and find the command. The command reference will usually describe the privilege level. Unfortunately I have found a few situations where the description of privilege level was not correct.
My advice is that if you want to find the privilege level for some commands that you want to manipulate, that you get a router and try the command and determine what its privilege level is.
HTH
Rick
HTH
Rick