/usr/share/php/Icinga/Data/Filter/ is in php-icinga 2.1.0-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Icinga/Data/Filter/Filter.php
/usr/share/php/Icinga/Data/Filter/FilterAnd.php
/usr/share/php/Icinga/Data/Filter/FilterChain.php
/usr/share/php/Icinga/Data/Filter/FilterEqual.php
/usr/share/php/Icinga/Data/Filter/FilterEqualOrGreaterThan.php
/usr/share/php/Icinga/Data/Filter/FilterEqualOrLessThan.php
/usr/share/php/Icinga/Data/Filter/FilterException.php
/usr/share/php/Icinga/Data/Filter/FilterExpression.php
/usr/share/php/Icinga/Data/Filter/FilterGreaterThan.php
/usr/share/php/Icinga/Data/Filter/FilterLessThan.php
/usr/share/php/Icinga/Data/Filter/FilterMatch.php
/usr/share/php/Icinga/Data/Filter/FilterMatchNot.php
/usr/share/php/Icinga/Data/Filter/FilterNot.php
/usr/share/php/Icinga/Data/Filter/FilterNotEqual.php
/usr/share/php/Icinga/Data/Filter/FilterOr.php
/usr/share/php/Icinga/Data/Filter/FilterParseException.php
/usr/share/php/Icinga/Data/Filter/FilterQueryString.php