How to send column/fields to subreport as collection in jasper

[phillip.sdao]

So I've been able to make a second data source, pass down parameters, im all but ready, but I cant figure out how to send a collection of the field values in a column to the sub report. Ive tried setting a variable to the field value and sending that, I've tried sending the field directly.

I sort of assumed these wouldn't work because the data type is wrong, but i just don't know how to tell jasper that i want the fields as a collection.