Hello Parijat,
I have created a knowledge entry on how to use that new import feature in OPM SS5. You can find it here: communities.bentley.com/.../8569.aspx
Please, let me know if it is clear enough and if it works fine for you.
As for the levels for services. You should use the BY_TEMPLATE symbology, and define which level is used for each service in the element template:
1. Change OP_SYMBOLOGY_PIPING to "BY_TEMPLATE:OpenPlant\Piping\" & PIPELINE.SERVICE_NAME & ":Model";
2. Add the required levels with desired colors in the dgnlib file;
3. In the Element Templates, define a template for each service, which would point to a correct level:
Hope this information helps, and let me know if you have additional questions.
Regards,
Justinas