To be clear, there are visit, filter and action functions for pipeline members, network extensions, and objects of pipeline series. I would highly recommend reading the API Wizard under User's Guide->Production Applications: Piping->Piping Terminology. There is a great explanation of each object type within.
To acquire a handle to one of the various objects (there is no specific object type for this, it's a ProFeature) I would start with the following:
1. Use ProSolidFeatVisit to visit all objects of type PRO_FEAT_PIPE_* by filtering in the filter function. Read ProFeattype.h for all applicable types. I found the following possibilities.
#define PRO_FEAT_PIPE 945
#define PRO_FEAT_PIPE_SET_START 1020
#define PRO_FEAT_PIPE_PNT_PNT 1021
#define PRO_FEAT_PIPE_EXT 1022
#define PRO_FEAT_PIPE_TRIM 1023
#define PRO_FEAT_PIPE_FOLL 1024
#define PRO_FEAT_PIPE_JOIN 1025
#define PRO_FEAT_PIPE_LINE 1027
#define PRO_FEAT_SLD_PIPE 1029
#define PRO_FEAT_PIPE_JOINT 1032
#define PRO_FEAT_PIPE_BRANCH 1033
2. Then in the action function use the appropriate ProP* function on the ProFeature object to get the data of interest. For example to get the pipeline network I would use ProPipelineNetworkEval(p_feat, &pro_pNetwork);
Hope it helps!
