This is a little weak, grammatically. For the first half, the first question I have as a reader is, what is "it"? Before you use an abstract pronoun like "it" you need to identify what "it" is. I would re-phrase it as, "It refers to the training that is required for all employees, but especially for management. HR is responsible for implementing and supervising the training. They will also work to improve the training process."

It refers to the training that all employees especially the grassroots manager,need to know; HR is responsible for implementing the training and supervision of the plan,evaluating the implementation and asking for improvement.