You will not lose any data by changing versions or updating the Business Directory plugin. You won’t even lose any Business Directory data by deleting the plugin all together and reinstalling it! (although you may need to re-save your permalinks)
Note: All of the Chamber Directory plugins need the Business Directory plugin to be installed & activated in order to work. If you delete the Directory, the other Chamber Directory plugins will be deactivated. You will need to re-activate them once you have re-installed the Business Directory.