My man
Your new employer will be looking for references who can provide information and context around how you are to work with, how you have dealt with complexity and how you show initiative.
They will ideally want to understand how you work and how you behave.
You NEED someone you have worked with directly or who has managed you.
Highly suggest you find someone at your current workplace ideally someone at a more senior level to you. Or someone at same level that can vouch that you can rely on.
What is the worst case at your current place if they know you are interviewing?
Motorheads