Requirement for managerial position to be held outside the US for at least one year in the 3 years preceeding the filing of EB1 petition.
That said I would suggest consulting your employer’s immigration lawyer to explore your qualifications around EB1 as it is a complex category.
Excerpts from USCIS.
You must have worked in a managerial or executive capacity for a firm or corporation outside the United States for at least one year during the three years before submitting your petition, and you must seek to enter the United States to continue service for that firm or organization. Your employment must have been with the same employer, an affiliate, or a subsidiary of the employer. Your employer must:
Be a U.S. employer; and
Have been doing business for at least one year as an affiliate, a subsidiary, or as the same corporation or other legal entity that employed you abroad.
If you want to dive into more details, below is the policy manual.