As per the guidelines of CEFRL (Common European Framework of Reference for Languages) these are the things learners are supposed to be able to do once they are at the B2 level.
Listening: They can understand extended speech and lectures and follow even complex lines of argument provided the topic is reasonably familiar. They can understand most TV news and current affairs programmes. They can understand the majority of films in standard dialect.
Reading: They can read articles and reports concerned with contemporary problems in which the writers adopt particular attitudes or viewpoints. They can understand contemporary literary prose.
Spoken interaction: They can interact with a degree of fluency and spontaneity that makes regular interaction with native speakers quite possible. They can take an active part in discussion in familiar contexts, accounting for and sustaining my views.
Spoken production: They can present clear, detailed descriptions on a wide range of subjects related to my field of interest. They can explain a viewpoint on a topical issue giving the advantages and disadvantages of various options.
Writing: They can write clear, detailed text on a wide range of subjects related to my interests. They can write an essay or report, passing on information or giving reasons in support of or against a particular point of view. They can write letters highlighting the personal significance of events and experiences.
In short, learners with a B2 level :
Can understand the main ideas of complex text on both concrete and abstract topics, including technical discussions in their field of specialisation.
Can interact with a degree of fluency and spontaneity that makes regular interaction with native speakers quite possible without strain for either party.
Can produce clear, detailed text on a wide range of subjects and explain a viewpoint on a topical issue giving the advantages and disadvantages of various options.
The B2 level is asked from students who are aiming to study in the French public Universities.