Under geometry input, there is an option for "Bottom panel". I do not understand what this does. When a value is input, the graphic makes it look like the bottom of the panel is buried in the footing. I'm trying to figure out how to model the geometry and loading condition of a tiltup wall at a dock without the slab tied into the wall for support.
The bottom panel is below grade like a foundation wall. It's excluded from things like out-of-plane wind loading. If you don't want that behavior, but still want the wall to go below the openings, just model a taller first level and place the openings with some vertical offset, like windows vs. doors.