What employer of M0 was acquired by M1 , acquired M3 , was acquired by M2 , and acquired M4
SELECT DISTINCT ?x0 WHERE {
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M0 .
?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M1 .
?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2 .
?x0 ns:organization.organization.companies_acquired/ns:business.acquisition.company_acquired M3 .
?x0 ns:organization.organization.companies_acquired/ns:business.acquisition.company_acquired M4
}