Grouped exposed filter is not available I'm trying to create a filter within a view, which has multiple ranges;

i.e. 


0-99
100-399
400-699
700-1000


I have seen this before when you Add filter criteria, you can select grouped exposed filter and I can set up the ranges in there. But in this instance, this option is not there and I'm not sure why not.

In the drupal code I found Drupal API which counts the options in $this-&gt;operator_options() - But I don't know what $this-&gt;operator_options() is meant to contain, or how you go about adding items to it through the back-end.
Did you try Facet API filters? check the Facet API module

The Facet API module allows site builders to easily create and manage faceted search interfaces. In addition to the UI components that come out of the box, themers and module developers can build their own widgets that can optionally be contributed back to Drupal.org. Facet API works with the core Search, Search API, and Apache Solr Search Integration modules (including Acquia Search) meaning that code and configuration can be reused as-is with the most popular search solutions available to Drupal. Refer to the documentation for more details.