You could write it like this:
pctin((q1 >= 1 and q1 <=5) or q2==2, true)
Or you could use the inrange function:
pctin(inrange(q1,1,5) or q2==2, true)
You're basically saying: compute the percent of records where ((q1 is within 1 and 5) or (q2 equals 2)) is true.