If a person has an approved I 130, can they apply for another I 130 through a different relation

And answer is Yes and No at the same time. It is because you are asking two questions in essence. 1. Who can file the I -130. 2. Can an I -130 be filed by two different family based petitioners for the same beneficiary.  As to the first question, the answer is "no". Only a qualified relative of the prospective beneficiary can be a petitioner. Beneficiary, cannot self petition.    As to the second question, the answer must be "yes". A beneficiary can be petitioned as such by any number of eligibile petitioners. That is true even if one of the petitioners is the person's prospective employer.