/usr/include/ql/experimental/exoticoptions/ is in libquantlib0-dev 1.4-2+b1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ql/experimental/exoticoptions/all.hpp
/usr/include/ql/experimental/exoticoptions/analyticamericanmargrabeengine.hpp
/usr/include/ql/experimental/exoticoptions/analyticeuropeanmargrabeengine.hpp
/usr/include/ql/experimental/exoticoptions/analyticpdfhestonengine.hpp
/usr/include/ql/experimental/exoticoptions/analyticsimplechooserengine.hpp
/usr/include/ql/experimental/exoticoptions/analytictwoassetbarrierengine.hpp
/usr/include/ql/experimental/exoticoptions/analyticwriterextensibleoptionengine.hpp
/usr/include/ql/experimental/exoticoptions/continuousarithmeticasianlevyengine.hpp
/usr/include/ql/experimental/exoticoptions/everestoption.hpp
/usr/include/ql/experimental/exoticoptions/himalayaoption.hpp
/usr/include/ql/experimental/exoticoptions/kirkspreadoptionengine.hpp
/usr/include/ql/experimental/exoticoptions/margrabeoption.hpp
/usr/include/ql/experimental/exoticoptions/mceverestengine.hpp
/usr/include/ql/experimental/exoticoptions/mchimalayaengine.hpp
/usr/include/ql/experimental/exoticoptions/mcpagodaengine.hpp
/usr/include/ql/experimental/exoticoptions/pagodaoption.hpp
/usr/include/ql/experimental/exoticoptions/simplechooseroption.hpp
/usr/include/ql/experimental/exoticoptions/spreadoption.hpp
/usr/include/ql/experimental/exoticoptions/twoassetbarrieroption.hpp
/usr/include/ql/experimental/exoticoptions/writerextensibleoption.hpp