Retreva understands you may have one file but want the contacts loaded to different contact groups. Retreva supports groups on the upload.
Add a column to your spreadsheet. Label the group names, anything you want. Or add an EXISTING group name that EXACTLY matches your existing Retreva group. Then, match that column to the group_name in Retreva during the upload process.
Your contacts will be uploaded to the different groups. Note that you still have to pick a default group (like no campaign), but only contacts without a group name will be loaded to the default group.
Below is a blank template that you can download. This contains our most popular fields, but you can map additional columns to fields in Retreva. Keep in mind that if you are loading to active groups, emails might send immediately or during the next scheduled campaign window.