You want to create a BOM based on certain elements in a structure or certain selected elements. This video will show how to accomplish this.
You can create a querie in Advance Steel of certain criteria in your structure based on your selected preference in the Search filter. The Search filter is located on the Advance Steel Management Tools Palette, selection category.
You can create queries based on the object type, Common properties, Number and object Partmarks along with naming, model role, Lot/Phase etc. You can then export the customized BOM in various formats and save it to the automatically created BOM folder of the structure.