Why script parameter doesn't work as the instrument parameter?

Question

Hello. Tell me, please, can I solve this problem? There is instrument TopoToRaster and it has parameter "In Topo Features", so when I running it, I can choose what fields to calculate:

The same thing is in model, created in ModelBuilder.
But when I use script with that parameter, I can't choose fields:

How can I avoid manual input?

helloworld · Answer

Thanks, it's really looks like what I need, but I haven't found how to work with the "Topological Objects" parameter:

I read about Multiple parameters, but it didn't help me, because I have some kind of table with fields, not the single field as in these examples.

How can I get access to the highlighted field (№2 on the image)? I just want to make that simple field (2) as a list of fields from (1), like this:

JonathanQuinn · Answer

None of your pictures came through but it sounds like you're interested in script tool validation, which is only possible using Python and a script tool.  If that's the case, you'll want to use a filter to find the fields in the input and then update a parameter based on those fields.