L-1: transferring within your company to the US
The L-1 moves an employee from a company abroad to a parent, subsidiary, branch or affiliate in the United States. L-1A is for managers and executives (up to 7 years), L-1B for specialised knowledge (up to 5). You need at least 1 continuous year with the foreign entity in the last 3. A new US office can sponsor an L-1A for its first year on a business plan. The L-1A leads naturally to the EB-1C multinational manager green card, with no labor certification.
Education, not legal advice.
Talk to an attorney who does L-1 work