§ 8-107

(a) An individual who performs services for an employer that maintains more than 1 establishment is deemed to be employed by a single employer.

(b) If an employer has actual or constructive knowledge that an individual is employed to perform or assist in performing the work of any agent or employee of the employer, the individual is deemed to be employed by the employer regardless of whether the individual was hired or paid directly by the employer or the agent or employee of the employer.