I created a User List based off of a multiselect drop down menu field. The field is NOT required and so I want the list to only show people that haved selected something from this field. I thought the way to do that was to set the filter as 'Position Is NOT Null' (position is the name of the field) but when I do that it shows them but it shows others that have nothing for that field.

This field is not viewable during registration. Only after one logs in and edits their additional info is it viewable. It seems that what is happening is it adds anyone to my userlist that simply logs in and edits their additional info.

Is this a bug or am I am idiot?