Session Buddy v3 (now deprecated) stored Saved Sessions, Previous Sessions, and settings in a single file on your computer.
To locate that file, follow these steps:
1. Find the current Chrome profile folder
A Session Buddy installation is specific to a Chrome profile.
To find the folder path for the current Chrome profile, see: How to Locate the Current Chrome Profile Folder.
2. Find the Session Buddy database file
Go to the location of the Chrome profile obtained in Step 1.
From this folder, go to the subfolder named databases.
From there, go to the subfolder named chrome-extension_edacconmaakjimmfgnblocblbcdcpbko_0.
This folder contains your Session Buddy v3 database file. The file will have a numeric name like 1 or 2.
If there is more than one such file, the current file is the one with the highest number. This should also be the file with the most recent modification date and largest size.