The easiest way to determine database user for a SAP B1 company database is checking the SLD using the method described in the topic "Before add-on installation".
But if that is not an option and the SAP B1 server is running on HANA the following can be done as an alternative.
1.Open SAP HANA Studio.
2.Go to Security.
3.Go to Users.
4.Go through each of the user that start with B1_ and ends with _RW and one by one do the following:
a.Double click the user.
b.Go to the Object Privileges tab.
c.If a SAP B1 company database is listed among then the user is the SAP B1 database user for that database.
For example, the user in the image below is the database user for a B1IC_DK database:
