Are you obligated to hire an attorney from the state you were divorced in IF you no longer live in that state anymore?

Ex-husband and wife divorced in the state of AR. The ex-husband has to take the ex-wife back to court to request amendments to his visitation schedule, from the original divorce decree since he no longer lives in the same state as his ex-wife & children, any longer but now resides in, MI. Is he obligated to hire an attorney from the state in which the divorce took place/was finalized (AR) or can he hire an attorney from the current state he resides in? Is there out of state mediation that can be administered due to the proximity of distance between the two parties and if mediation is not an option and appearing in court is necessary, IF able to hire an attorney from his current state of residency (MI) will he & attorney be forced to travel back to AR for the trial hearing, concerning changing the visitation schedule? His employment required him to leave the state in which he was previous living/divorced in.