Unable to link 'Lookup Type' to Source 'Work Order SubType' in Manage Subledger App. trans. Objects

Summary:

Unable to link 'Lookup Type' to Source 'Work Order Subtype' in setup 'Manage Subledger Application Transaction Objects'

Content (please ensure you mask any confidential information):

n a Mapping set using Segment rule, Requirement is to derive Accounts based on Work order Subtype.

For the input Source as Workorder Subtype while creating the Mapping set, there is no linkage to 'LOOKUP TYPE' - ORA_MNT_WO_SUB_TYPE (a seeded Maintenance Management Lookup for Workorder Subtype)

Then when checked in the setup 'Manage Subledger Application Transaction Objects', the value for LOOKUP TYPE' is blank.

Unable to see an option to associate the same, how to associate the LOOKUP TYPE' - ORA_MNT_WO_SUB_TYPE to Source Workorder Subtype.