Personnel file - help!

單身老貓and other friends,

March 26 I was laid off by my company.
In the 8 years if my employment I had many issues with the company,
mainly discrimination and retaliation.
And recently I got treaded so badly that I took 3 weeks off on medical leave

I already got a job offer pending my background checking.
In my personnel files, there are all sorts if record,
will my company give my whole record? I will look very bad.

Please help, thank you so much!