Enjoying travel is something almost everyone has in common.
Literal
Travel [object-を] enjoy [nominalizer-の] [topic-は], almost all people [to-に] is-common.
~に共通している (to be common to / shared by) uses に for the group sharing the trait. ほとんどすべての人達 (almost all people) hedges slightly with ほとんど. The sentence claims travel enjoyment as a near-universal human trait.