In ProjectWise Design Integration, each document can have an Environment assigned to it which defines document Attributes. These are displayed for each document when viewing the document's properties in PW Explorer. 

These Attributes (and their parent Environment) are defined in the PW Administrator tool.

Each Environment name is used as a subclass under the iModel's DocumentMetaData schema.  This can currently be access in imodelconsole.bentley.com using 2 simple queries:

First is to select from the DocumentMetaData schema using "Select * from DocumentMetaData.DocumentLink".  This retrieves all documents in the iModel.

The sub-classed environments are listed as "ProjectWiseDynamic.Env" followed by the PW internal environment identifier followed by the Environment name (in this case "MyCompany").

Querying the sub-classed name directly results in all the documents and attribute values for that environment ion the iModel.

When viewed in Design Review the data can be seen when clicking on an element, and viewing it's properties under the Document Link group property:

Further information can be found on Bentley's YouTube channel here: