RosettaCodeData/Task/Find-common-directory-path/BQN/find-common-directory-path.bqn

LongestPath ← {∾⟜𝕨⊸∾´ ⊑¨{1⊸+⌈´/≤⟜1¨≠¨𝕩}⊸↑ ⍷¨⥊⋈˘ ⍉> ⌊´∘(≠¨)⊸(↑¨) 𝕨⊸((+`׬)⊸-∘= ⊔ ⊢)¨ 𝕩}

dirs ← ⟨
    "/home/user1/tmp/coverage/test",
    "/home/user1/tmp/covert/operator",
    "/home/user1/tmp/coven/members",
⟩

•Show '/' LongestPath dirs