I am a generalist Training Manager supporting mostly local ops. But I did get a chance to report into a generalist "HR Director" (inflated title) and then later to a HRBP when she came in & replace the Director who was asked to leave.

This is just base on my observation, so maybe a BP can correct me. To me the biggest difference is a normal HR manager is like a office support while a BP is more of a GM who has a focus on manpower related issues.

My previous boss the HR Director was a very typical HR person, a late 40s nice lady who rose from the ranks and started out as a HR Officer. She knows recruitment process, employment law issues, done payroll before & knows a bit of training stuff.

She tend to play a support role like when GM say hire 50 operator, she will instruct us to kick start the hiring and conduct interviews, run road shows. If staff complain about welfare, she will look into it and make changes to benefits. When come to performance appraisal, her main job is to make sure everyone submit on time and bonus paid out accordingly. Whatever corp reporting need to do, she will fill up the templates and get us to compile data.

When my new boss the HRBP came, things were very different. New boss was a very energetic and driven young lady in her mid 30s, but paid nearly twice my old boss. Big difference is within a short time she know a lot about the business. Each SKU we produce, margins of our brand portfolio, capacity expansion plans over the next 3 years, our supply chain vendor mgt framework, sales distro model etc. She also hired 1 analyst who churned out a lot of HR analytics like efficiency ratios, productivity, turnover trends, training costs, succession pipelines etc. I had a hard time adapting to her style at first.

I also notice new boss is more politically savvy compared to my old boss who is like friendly to everyone. She know how to play politics, influence stakeholders, maintain good relations with powerful people in RHQ. She also tend to be able to challenge GM on best practices, the assumptions they put in the planning and budgets, organization structure and always debating with the Finance Director over costs & performance measurement. In a nutshell, she was much more pro-active & powerful in the business compared to old boss who basically take instruction from top and make sure her own HR department is run well.

Old boss was a more pleasant person to work with, but I learn more from new boss. Anyway I told her recently I want to move into a specialist role in Learning & Development and she is quite supportive and try to talk to the RHQ team to consider my transfer, but in the end didn't get it, they say I didn't have relevant experience.

This is my 2c, hope this helps.