Choice of two input files in Model Builder

[SachinChand]

I'm trying to create a model in AGS Pro that exports selected features in a map, to CAD. It is comprised of two nested models, the first model collects and manipulates the features and the second model (screenshot below) does the actual export to CAD. The export will use one of two "seed" files in the export tool. How can I setup the model to provide a choice of the two files with one of them set as the default?

[ShitijMehta]

Hi,
possible to re-add the screenshot? I don't think it came through or i just cant see it. Thanks!

[SachinChand]

This is the second of the nested models and contains just the export to cad geoprocessing tool.  I want to make the seed file a choice of two files.