I do something like this...
In DBrix notebook:
dbutils.widgets.text("runDateYYYYMMDD", "")
runDate = dbutils.widgets.get("runDateYYYYMMDD")
In Data Factory:
Pipeline > Parameters tab > New Parameter:
Name: RunDate, Type:String, Default Value:
Data Bricks Notebook Activity > Settings tab > New Base Parameter:
Name=runDateYYYYMMDD, Value=pipeline().parameters.RunDate