I am sorry, Robert, but ArcGIS Desktop cannot directly access libraries from Microstation. However, when DGN files from Microstation are brought into ArcGIS Desktop, either by displaying the data in ArcMap, or importing the data using CAD to Geodatabase, the Level information for the features is preserved in the attribute tables for the data. The symbology for the data can then be set based on the Level on which the data was created in Microstation. ArcMap does a reasonable job of duplicating the symbology for CAD files, both for Microstation and AutoCAD, when the data are drawn in ArcMap, but the symbology needs to be reset if the data are imported to a geodatabase. If you have created custom symbols in Microstation for the data, it will be necessary to reproduce those symbols in the ArcMap Style Manager dialog.
Margaret
Esri Support Services analyst