Did a company that M1 founded and was employed by employ M2 and employ M3
SELECT count(*) WHERE {
?x0 a ns:business.employer .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
?x0 ns:organization.organization.founders M1
}