Conditional Formatting with muliple conditions - A "how to" question.

I use this Red/Green fill expression which works

=iif(Fields!ES_RIIR.Value<=Fields!ES_Limit_Value.Value,"Lime","Red")

However, do not want to use it if some of the cells fall under a certain group, for example here is an expression I use for hiding data in a cell:

=iif(Fields!Location_Level_2.Value like "AAA" or Fields!Location_Level_2.Value like "BBB",True,False)

Basically I want to join the two when doing a fill format.  So only do red/green fill (the first expression) if they do not belong to AAA or BBB.

How would I do that?