Please use following example to remove or adding new salary range.

Remove existing salary ranges

function job_bm_rb_filters_salary_range_extra($salary_range){

  unset($salary_range['10001-20000']);

  return $salary_range;
}

add_filter('job_bm_rb_filters_salary_range','job_bm_rb_filters_salary_range_extra');

Default salary ranges are

1000-10000
10001-20000
20001-30000
30001-50000
50001-80000

Add new salary range

function job_bm_rb_filters_salary_range_extra($salary_range){

  $salary_range['1500-2000']='1,500-2,000';

  return $salary_range;
}

add_filter('job_bm_rb_filters_salary_range','job_bm_rb_filters_salary_range_extra');