Security Question: I can I restrict access to legal regs?

Hi, I have a security question.

When a user goes to transaction /SAPSLL/BL_DOCS_EXP

selects the row of a specific document

clicks on the Change Prod. Master icon

the user is navigated to the Change Products Legal Control tab /screen (but the transaction still says /SAPSLL/BL_DOCS_EXP

I want to restrict the user to only be able to change specific legal regs

Any ideas?

I looked at the authorizations set up for my role and I don't see one that I can utilize for this purpose.

Thank you, Mikki