Make A DFF required based on Supplier field or based on another DFF Value ?

Summary

Show or make a DFF required based on supplier field value or another DFF

Content

We have a requirement to show or make a DFF required based on :

1- When supplier field is filled (any value exits)

Or 

2- When another DFF field is filled with specific value 

Appreciate your support please thank you.

Show or required both works for us