BACKGROUND:
Whenever Base is attached to an external database, the exact path of the external database file must be specified.  Because this is likely to be unique to the filesystem structure on each user's hard drive, it makes it difficult to distribute split databases to other potential users.  Each end user must be educated enough to edit the Base document's connection settings to connect to the back end database.

I propose a mechanism where the current Base document's directory could be specified as the location of the back-end database.  This way as long as a back-end database file and the front end Base document file are kept together, there won't be any need for end users to edit connection settings, no matter what the filesystem structure is or if the files are later moved.

IMPLEMENTATION:
I propose two implementations depending on whether the back-end database is directly supported by Base (MS Access, MS Access 2007, Spreadsheet, dBase), or if it's based on a connection string like ADO, ODBC, and JDBC.

For file-based external back-end databases that are supported directly by LO(MS Access, MS Access 2007, Spreadsheet, dBase), you specify where the back-end database file is using a standard file requester dialog.  I propose that after the user clicks "Ok" on this, that LO Base should detect if the selected file is in the same directory as the current document.  If it is, then have Base automatically add an internal flag to the Base document that tells Base to , in the future, always look for the database file first in the Base document's directory.  The full path of the database file will still be stored, so that in the future if the user moves the Base document but not the back-end database file, then Base can still look there for it.

For connection-string based back-end databases (ADO, ODBC, JDBC), I propose supporting an environment-variable-like macro expansion in the connection string where, for example, %DOCUDIR% expands to be the full patch directory of the current Base document.  Thus, a JDBC connection string could be: "jdbc:sqlite:%DOCUDIR%/database.db"