You can import more properties to the redefined service by following below procedure:
Base service must have an ABAP structure assigned to import more properties to the redefined service
In the tree view, right click the entity and click Import.
Click Properties. Wizard Step 1 of 2: Import Properties displays
In this wizard previously imported properties remains disabled and others enabled and selectable. Select the property you want to import
Click Finish in Wizard Step 2 of 2: Import Properties .
Thus, selected property is imported and can be viewed under the entity in tree view.
Importing properties, in the redefined projects, is possible only in SAP Gateway SP09 and higher versions.