Privacy Rules Best Practice

Need help Database
1

I have datatype X and fields called a ( list of things ) and b ( list of things )
what is the efficient way to set up privacy rules here to make X visible for things in a or b
AND
Is there another way to set up that with new structure to avoid lists ?

I will be happy to hear from anyone.

2

Hmm is there any suggestion or it was one of limitation pf privacy rules ?