You can look up the File ID of your asset by looking at the View->Dependencies dialog. Locate the ResourceManager_Dependency that belongs to the asset with (Base) by searching for the Path ID (make sure it also appears under m_Container with the same m_FileID and the correct name), and add your asset to the container by inserting a new entry to m_Dependencies with your asset's Path ID and the proper File ID.
2.2 beta 2 (Happy New Year edition) is out with Unity 2017.3 support and bug fixes!Ĭurrently, the best way is to edit the json dump of the ResourceManager asset (Export Dump, select json instead of txt).