Hi @Irena Dempster? , thank you for your question!
When you have a column of an object data type, you can click on the column's header (the column name), and one of Trifacta's suggestions will be to "unnest values into columns".
In this suggestion, Trifacta will unnest all of the possible keys in this column; Where they don't exist, a blank will be shown.
I hope that helps. Please feel free to ask any additional questions.
Thanks,
Amit.