Which company that M1 was employed by and founded was a person 's employer
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:business.employer .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person ?x1 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1 .
?x0 ns:organization.organization.founders M1 .
?x1 a ns:people.person
}