The Joined List computed column joins or concatenates many values into a single text value. For example, it could join the list of names:
Into a text list like "Alice, Bob, Susan".
The Joined List column also allows you to choose how you separate these different values. By default, all values are separated by a comma. You can add whatever you want as a separator, including a value from another column.
In the Data Editor, open the table you want to edit.
Add a new column by clicking the plus (+) symbol to the right of the table.
New columns added with the plus button will always appear on the right. If you'd like to add a column somewhere else in your data, you can select the dropdown menu on an existing column and choose Add column right. You can also click and drag columns to rearrange them.
Give the column a name.
For Type, search for Joined List or navigate to Computed → Joined List.
Choose the column where the text is that should be joined.
Choose a symbol or data to use as the separator.