/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/ is in libgtkdataboxmm-dev 0.9.4-3build1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/bars.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/cross_simple.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/databox.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/graph.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/grid.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/init.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/lines.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/markers.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/points.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/bars_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/cross_simple_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/databox_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/graph_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/grid_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/lines_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/markers_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/points_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/ruler_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/scale_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/private/xyc_graph_p.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/ruler.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/scale.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/wrap_init.h
/usr/include/gtkdataboxmm-0.9/gtkdataboxmm/xyc_graph.h