About Opening Mirrored Parts in Part Mode
Mirrored parts that were created using Geometry only or Geometry with features can be opened in Part mode and placed in assemblies other than the one in which they were initially created, regardless of the location of the original part.
By default, when you open this type of model in Part mode, the source part is not loaded into session. Set the retrieve_merge_ref_parts configuration option to yes to retrieve the source part when the mirrored part is opened.
The configuration option retrieve_data_sharing_ref_parts controls the general settings of all types of referenced parts. When you leave this configuration option in the default state (no) and change the retrieve_merge_ref_parts configuration option to yes, only source parts of mirrored parts are loaded into session.