When building a group using fields, I think it's important to have a way to say (this) or (that) AND (this other thing), instead of just ANY of these things or ALL of these things.
This feature is currently available by using the group 'nesting' function on the group builder page. You will need to be in the Advanced view of the group builder for this feature to be usable. Please let us know if you need any help in using the nesting function.