Hello, for jump storey or built-in skirting boards, it is recommended to create them by free modeling or skirting board mapping. The operations are as follows:

Method 1: Draw an auxiliary line, position the height, click the path direction, select the skirting board section, click Select, and then modify the skirting board size in the lower left corner;

Method 2: Click on the wall - dividing line - divide the wall - click on the size below the dividing line to modify the height of the skirting board/top line, drag the decorative mapping - skirting board.

The operation of the old version interface is as follows: