Try always to split your code in small functions that do a single thing, I would do it like this:
getUserExperience(user:Object):Number
implement this function first do some test and after you get it o return the correct experience then you can go to the next step to make the filter function.
Write some code to compute the min and max experience for the filter
var min:Number=startYear.value;
var max:Number=endYear.value;//if needed adjust this to seome default values
now the filtering should be easy because you just have numbers and no UI components and Objects so the filter will need to check a simple thing
var userExp:Number=getUserExperience(user);
var response:Boolean=mio<=userExp&&userExp<=max;
return response;
I am sure after you refactor your code to be simple and clear it will be easy to fix any bugs