User select the filter criteria current_salary_range is 20000. I will show the results also salary range below 20000 I have created the content type named candidate_profile, included fields like Current_Salary_Range.

I have created a view and also I am using better exposed filter for current_salary_range field.

My  question is: When the user selects the filter criteria current_salary_range of 20000, I want to show the results who is having current_salary_range 20000 and also who is having current salary range below 20000.

how to proceed with this...?
In your Content type Manage Fields, what you need to do is make the Current_Salary_Range FIELD TYPE be a (number) Integer field and not a text field. 


  Note: You will have to delete and create a new field, as you cannot change field type after the field has been created


Then when you add it as a filter in your view, you should get the option of less than or equal to



Note: picture is from Drupal 8, but should be the same in Drupal 7.