Hi @abidoua, creating an IFC dataset requires some data transformations with transformers, so it's hard to specify issues unless it's clear what you have done so far.

Firstly see Knowledge Center articles to learn how to write an IFC dataset. I think this one would be a good starting point: AutoCAD to IFC Conversion Example

i need to translat from CityGML to IFC

It could help to give some more information, would you mind posting a sample data set and your workbench so others can play with the 'same' data as you are working with now.