In Edit Measures window, after selecting multiple variables and clicking the ellipsis menu, an option to "multi-var combine as discrete values" would create syntax like this:

pctin(
          in(B4_1,5,7,12,16)
       or in(B4_2,5,7,12,16)
       or in(B4_3,5,7,12,16)
       or in(B4_4,5,7,12,16)
,true)