Is the database you are looking for a child to another database? You can change the Data Source Explorer view to show all the databases in a flat view (not hierarchical) by changing a preference. Go to Window>Preferences>Teradata Datatools Preferences>Data Source Explorer Load Preferences and uncheck the 'Show Databases and Users in Hierarchical Display' option.
Is the database you are looking for a child to another database? You can change the Data Source Explorer view to show all the databases in a flat view (not hierarchical) by changing a preference. Go to Window>Preferences>Teradata Datatools Preferences>Data Source Explorer Load Preferences and uncheck the 'Show Databases and Users in Hierarchical Display' option.