In most cases, the files containing your *Aliases* 'travels' with your Instant Database records. But this is just the default action. You can store your *Aliases* anywhere you want and share them with anyone.
The *Alias* names and the multiple choice lists they represent are stored in a file called "multichoice.csv". Initially, this file is located in the folder c:\program files\pathagoras\idbs". (The folder "idbs" is where your Instant Database records are stored.)
To move (or find, if missing) your MultiChoice Lists using Pathagoras, click the All Settings button from the Utilities/Settings screen.
From the resulting All Settings screen (shown below), click the *Aliases* tab. This will display the current location of the multichoice.csv file. (At least this is where Pathagoras thinks it is. If the file was manually moved, or otherwise intentionally or accidentally relocated, this is the last location recorded in your Windows registry.)
To move, or repoint to, the *Alias* List, click the ". . ." button. Navigate to the folder that either contains (if you are repointing) or that you want to contain (if moving) the *Alias* List.