Filters of the type LDAP_FILTER_SUBSTRINGS generally compare a set of substrings against an attribute. For example:
This filter finds entries in which the value of the cn attribute starts with John, contains Q, and ends with Public.
Call this function to get these substring values as well as the attribute type from this filter. In the case of the example above, calling this function gets the initial substring John, the any substring Q, and the final substring Public in addition to the attribute type cn.