What do you mean by the first-level and second-level catalogues of teacher recruitment?

The first-level catalogue is a big category of disciplines, and the second-level catalogue is several small categories divided into big categories.

The first-level catalogue is a major category of disciplines, and the second-level catalogue is several subcategories divided into major categories. For example, art is a major category, and your major art is a secondary catalogue subdivided under the major category of art.

Teacher recruitment is the teacher recruitment examination, that is, the entrance examination, which is a competitive post examination after obtaining the teacher qualification certificate.