Stand-alone filters in FM

[phoenixfire]

Hey can someone please help me out with this?
I have a stand alone filter where there are two conditions A and B. So the filter has to be basically A or B.
But again in each filter, I have an AND that needs to be used.
For eg., A has a condition a1 AND a2 AND a3.
B has a condition b1 AND b2 AND b3.

So basically the stand-alone filter has to be like this. (a1 AND a2 AND a3) OR (b1 AND b2 AND b3)
but when I look in the background, it shows up like this.
a1 AND a2 AND a3 OR b1 AND b2 AND b3.

It is actually two different criteria but shows up as a bunch.
Any help is appreciated. Thank u in advance.