When you define a continuous footing, you can use the command line to specify parameters:
Pick the beginning point:
Pick next point [Side / Offset]
where:
Side = the location of the definition axis of a continuous footing (upper, lower, central)
Offset = the distance from the lower or upper level of a continuous footing
Select wall(s)
Select object
Finish [Side / Offset]
where:
Side = the location of the definition axis of a continuous footing (upper, lower, central)
Offset = the distance from the lower or upper level of a continuous footing
Pick first point
Pick second point [Side / Offset]
Pick third point [Side / Offset]
where:
Side = the location of the definition axis of a continuous footing (upper, lower, central)
Offset = the distance from the lower or upper level of a continuous footing
Select object