I have the columns "Auto number", "I am following" and "Followed by". I manually maintain the "I am following" column by entering 1 or more IDs of other rows in blank-separated form. Now I would like to fill the "Followed by" column automatically by collecting all IDs of rows in which the respective row ID is mentioned in the "I am following" column.
I have tried to combine the JOIN COLLECT and CONTAINS functions, linke this:
=JOIN(COLLECT([ID]:[ID]; [
I am following]:[
I am following]; CONTAINS(ID@row, @cell), " "))
But I am failed.
Example: