Starting link, the SoS "Caucus Finder":
http://caucusfinder.sos.state.mn.us/
DFL, caucus page.
GOP, caucus page.
Two Googles, one for DFL, other for GOP.
The DFL has an online pdf form for its caucus Chair/Secretary to fill out and centrally file.
Presumably the GOP has something comparable, with finding it online being left to readers who wish to search.