Excuse me, is there a general gap among the staff of enterprise party branches? If you join, is it generally foreign or domestic?

There is something wrong with your understanding. Party branches in enterprises don't just do something, they can do odd jobs. All party member of the enterprise are members of the Party branch, and they must take part in the practical work in the front line. Only a few cadres are full-time party workers. When the organizational relationship is transferred to a unit, you are a member of the party branch, but you should make good arrangements for your work and tasks.