multiple scan angle filter

edit

How to filter out multiple segments of scan angle using laser filters package? Right now i am able to only segment out single segment of scan filter like:

scan_filter_chain:
- name: angle
  type: laser_filters/LaserScanAngularBoundsFilter
  params:
    lower_angle: -1.57
    upper_angle: 1.57

Here when i tired this param it is not working:

scan_filter_chain:
- name: angle
  type: laser_filters/LaserScanAngularBoundsFilter
  params:
    lower_angle: -1.5708
    upper_angle: -0.785398
- name: angle1
  type: laser_filters/LaserScanAngularBoundsFilter
  params:
    lower_angle: 0.785398
    upper_angle: 1.5708

Is their any way or other ros package which can do this function?