Hi Yuri,
In the Filter tab and then in the Digits Filter field..you should have "01289", if you want to filter just the 181, 280 and 191 numbers you have to use and if step or a switch step in the successful branch of the Get Digit String.
if ( getDigitString == "181" || getDigitString == "280" || getDigitString == "191")
true
Do something
False
Do something else
Gabriel