This module allows contextual filter arguments and exposed filters to be used as replacement tokens in other filters or table arguments.
What this means:
You can use Contextual Filters (even Null ones) to accept arbitrary input, and use that input as values in one or more Filters (example: searching for node titles containing some search keyword).
You can reuse an exposed Filter value as a value in other Filters (example: users can search for nodes based on title or tag using one field by exposing a node's "Title" field and using input in that field in an OR non-exposed filter on taxonomy terms).