In principle, labor agreements set the framework conditions for salaries. The objective is to standardize structures and ensure fairness.
However, it is of course still possible to question and negotiate specific aspects. If you do not agree with the classification for your job, you can have it examined. This also applies to your classification. Here, it is also possible to apply for advance level promotion in the event of above-average performance or the acquisition of additional qualifications.
Additional benefits in kind can also be negotiated, like advanced training, which will then be paid by the Charité. It is best to talk to the relevant superior or contact the staff council with specific questions.