InfoPath Dev

I want to hide certain fields in an Infopath form, depending on the User's ID.

I have a list of 8 users who should be able to see everything, so I'm trying to use conditional formatting to hide the fields if the user isn't one of the users specified, for example:

As you can see, I am limited to 5 users, but I know that there is a way to group these rules using parentheses (like this:
http://www.infopathdev.com/forums/p/18475/64906.aspx). Can anyone advise me on the code I'd need to group these 5 rules please? I'm a complete newbie.

PS. I have tried many walkthroughs that teach you how to hide fields using UserGroups but not a single one has worked for me and i'm tearing my hair out.

For the first drop down in the very first condition, change the drop down from User ID to "The expression".

Then the condition will display the XPath expression for that condition! You can copy it out and put it in a text editor. Type the word  "or" after it, and then get the expression for the next one, and so on. Then you can paste your new expression into the text box for the expression you want to use - does that make sense?