I’m using a button to add an array to a column of arrays. If the row is blank ModifyRows() works fine to set the value to the new array.
The problem arises if the row already has a value. In the example below, the row value is set to ‘Shannon Drake’:
I have tried list() and listcombine() to add my value to the row, each time the existing value gets replaced as what looks like ‘Plain Text’ and loses its blue ‘array’ circle that denotes it’s lookup relationship. In this formula [User Member] is ‘Joseph Winke’ and thisRow.Assign exists as (Shannon Drake).
ModifyRows(thisRow, thisRow.Assign,list([User Member],thisRow.Assign)
Results in:
Hi @Johg_Ananda,
Unfortunately, it’s a bit more trickier.
It took some time to me to figure out how it actually works.
It’s (again) all about data types.
When you have a Lookup Column, you have either a row (single select) or multiple rows (multi select) references, which is not exactly a List() of rows.
Therefore, you need to simulate an actual lookup starting with the Table you are referring.
Basically, the overall outcome must come out from a filtering, not a composition.
I created a simple example which is perhaps explaining much better. I also added some explicative columns in the target table, so that you can debug and play around yourself.
Let me know if I correctly got your point and if it helps.
Very curious to see if somebody else faced this and found a better explanation/solution.
Cheers!
Thank you so much for helping me with this. Very clever and getting me to think different about my approach. I understand what you mean … I like the idea of list() working and I understand it might need to be like this. Thanks! 
You’re very welcome! 