Under Labor Code 2800 and 2802, your former employer has a duty to reimburse your for defense costs if you prevail. Your employer or its insurance company will likely provide a defense for you. If there are conflicts of interest between you and your former employer, you may need separate counsel. You should speak with them immediately. Fortunately, you and your employer are likely on the same side and will be able to find a way to work together.
I agree with my colleagues. I would just add that the only legal basis you can be held personally liable for damages is if the employee alleges and proves you harassed the employee because of age, sex, race, etc. Managers are not legally liable for acts of discrimination in the performance of their duties such as making termination decisions. While your ex-employer should defend you, it is a good idea to have your own lawyer advise you along the way.
They say you get what you pay for, and this response is free, so take it for what it is worth. This is my opinion based on very limited information. My opinion should not be taken as legal advice. For true advice, we would require a confidential consultation where I would ask you questions and get your complete story. This is a public forum, so remember, nothing here is confidential. Nor am I your attorney. I do not know who you are and you have not hired me to provide any legal service. To do so would require us to meet and sign written retainer agreement. My responses are intended for general information only.
Sometimes a lawyer will sue an individual to keep the case in state court. See if your former employer will defend you since you are being sued while you were employed at the other company. You can be held liable for harassment cases only. If your former employer won't defend you in the lawsuit you will need to retain your own attorney. But why pay for your own lawyer if the company will pay for your defense.
Best of luck.
I have seen a default enter as against a former employee where the employer could not locate the former employee and failed to provide a defense. It is important that you tender the lawsuit to your employer immediately. You may need an attorney to protect your rights, including your Labor Code 2802 rights to attorney fees paid for by your employer.
This answer is not a substitute for legal advice and it does not create an attorney-client relationship. Seek the advice of a licensed attorney before taking any action that may affect your rights