After submitting the job, use the Data Builder module to create a Machine and a Company. Machine and Company are entities used internally by Data Manager to classify the workspace that is in the scope of the masking and subsetting project. In Data Manager, a Machine/Company combination corresponds to a workspace.
Use the Data Subset Extraction module to create a Group. A Group is a label marking different methods to establish a set or a classification. A method is simply a set of rules applied to required tables, creating a test environment. In short, a method corresponds typically to a test environment. You can define different methods for the same table, creating different subsetted tables to test with different rules, but all starting from the same workspace.
See the Getting Started with z/OS Data Stores section in your Data Manager documentation for more information on workspaces and groups.