EDIT

This is implemented with a selection dialog, maybe it would be easier to use with a drop down, filled with the team members. But as a first implementation it can be used.

Seems to work as expected.

... no, not yet ready. After entering a team and a primary collector for a field unit and then setting the focus to another record in the derivative tree and then going back to the field unit the primary collector is shown in the collector field and the primary collector field is empty. Also the formatting is not correct (as it is as if the primary collector is the only collector). Looks like things are stored at the wrong place.

Andreas Müller wrote in #note-8:

... no, not yet ready. After entering a team and a primary collector for a field unit and then setting the focus to another record in the derivative tree and then going back to the field unit the primary collector is shown in the collector field and the primary collector field is empty. Also the formatting is not correct (as it is as if the primary collector is the only collector). Looks like things are stored at the wrong place.

This is fixed, please review.

Works as expected now.