You can draw your 2D drawings on different layers in GDL object '2D symbol' section. Or draw it first on the floor plan and paste into 2D symbol. Please note, that it does not support polylines. All polylines needs to be previously converted into lines and circles.
2D symbol has layers (like in ArchiCAD) but only with numbers - from 1 to 16.
Visibility of these layers can be controlled in 2D script via command:
FRAGMENT2 fragment_index, use_current_attributes_flag
Where
fragment_index
is number of layer and
use_current_attributes_flag
can be 0 or 1.
0 shows pens, line types and fills how it been drawn
1 replace these attributes with defined in the script (i.e. PEN number, LINE_TYPE number, FILL number)
You also need to create a parameter, let call it
symbolProjection
. Set it to number.
In parameter script use
VALUES{2} "symbolProjection" 1, "Top", 2, "Side", 3, "Bottom"
Then write in 2D script:
FRAGMENT2 symbolProjection, 0
That means if your projection will be "Top", symbolProjection=1 and it will show drawing on the layer 1.