If the city council decides to change the boundaries of the proposed business improvement district or to change the proposed modifications to the boundaries of an existing business improvement district or districts from those recommended by the business improvement board, the hearing shall be continued to a time at least fifteen days after such decision and the notice shall be given as prescribed in section 19-4029.01, showing the boundary amendments. The city council may not expand the proposed boundaries recommended by the business improvement board without the city council's proposed boundaries being considered by the business improvement board.