tried many different ways yet couldn't find any solution so far. checked all source code hoping to find an example yet nothing.
here is what I am trying to do:
food and ingredients ( aka nutrient ). ingredients must be selected once and not shown twice in drop-down.
i can control with domain to filter for first selection. no problem.
when adding another nutrient. (in the background) 'Vitamin A' is already on the list and that should be left out.
any idea how to achieve it ? keep in mind that record is still on create mode. nothing in db yet.
note: many2one and one2many widgets are able to do this filtering but not drop-downs