The chairman and the staff director of the District of Columbia's Alcoholic Beverage Control Board, both targets of a bribery and extortion probe by a federal grand jury, yesterday were given new city jobs with full pay pending the outcome of the investigation.

Robert C. Lewis, the ABC chairman and an architect by profession, will be dispatched to the design section of the Office of Planning and Development. Lewis's top aide, James E. Boardley, the board's staff director, was moved to the Department of Insurance, where he will be an administrative aide to the acting superintendent. They will start their new jobs today.

Boardley and Lewis will keep their current salaries and grade levels while working in their new jobs. Lewis was paid $50,112 a year and Boardley $30,844.

They were placed on administrative leave, with full salary, on Feb. 17, following the disclosure of the investigation into allegations that one or both of the officials threatened to make it difficult for developers of the new Hechinger Mall in Northeast Washington to get necessary liquor and building licenses for the mall unless a person designated by the officials was allowed to open a liquor store there, sources familiar with the probe said.

In announcing their new positions, City Administrator Elijah B. Rogers said Lewis and Boardley "have a right to come back" since they have not been charged with any crime. Rogers said that he was acting in accordance with city government personnel laws and added, "I have no discretion" in keeping the two men on the payroll.

Rogers said the investigation will not be compromised by the new jobs held by the two men since they will be removed from any contact with their old liquor board positions.

Lewis, who also held cabinet rank in the city government as the director of the Department of Licenses, Investigations and Inspections before he was placed on administrative leave, is a former city planner and has experience at his new job. Boardley will take on various administrative tasks as an assistant to James R. Montgomery.

Lewis was named director of the licensing department in January 1979, and later that year was named by Mayor Marion Barry to be chairman of the ABC Board. A month after he became licensing director, Lewis promoted Boardley from his post as an ABC investigator to head the liquor board's office staff.