I applied online. Got a telephone interview a month later, then was invited to attend an assessment day two weeks after that. Telephone interview was about 15mins. They mostly asked competency-based questions, what do you know about BMW, why do you want to work for us. Assessment day was slightly tougher. Had 20mins each to do two HR related exercises individually, then had to present our work to two sets of interviewers and answer a few questions. After that we had a SHL group exercise where the interviewers observed the five of us.