Man pages matching name dbix::oo::tree in section 3pm:

DBIx::OO::Tree.3pm.en	debian 10 / libdbix-oo-perl
DBIx::OO::Tree.3pm.en	debian 11 / libdbix-oo-perl
DBIx::OO::Tree.3pm.en	debian 12 / libdbix-oo-perl