Can we restrict editability of Buddypress profile as member feature

I was trying to work this out with URL Groups but with no success.
We have standard primary group profile fields that are available at signup and should remain editable and a second group that gives the user a way to edit extra data. This extra data is after signup but I would like to find a way to restrict access via Membership level or subscription as an inducement to pay.
I am also looking for a way to provide advanced search for this extra data and getting close but as yet "no cigar"
Cheers and thanks in advance.