How to show nested table column by using behavior

[amufaamo]

I am making task management app. Some tasks are flow, so I made 4 columns, "Unique ID", "Thing", "After", "Before". "Before" is virtual column.

Actual data is like below

Expression of "After" is below. I can choose rows.

The expression of "Before" is below.

select(not done task[Thing], in([_thisrow].[Thing], [after]))

When I select "Eat breakfast" row, I can see the tables of "make coffee" and "make bread".

I want to make view if I select "Eat breakfast", I can directly see the list of "make coffee" and "make bread".

I tried to make slice, the expression is below, but it shows nothing. Is something wrong?

IN([Thing], [_thisrow].[Before])

So sorry it is quite long sentence

[WillowMobileSys]

I don't see what is wrong but I believe you want "Before" to just be a single value.  Currently the SELECT() returns it as a list of values.  I would recommend using this slight modification and change the column data type to Text:

ANY(select(not done task[Thing], in([_thisrow].[Thing], [after])))

For the slice, you then want to change it so that it checks if [Thing] is in ANY of the Before columns for the entire table.  Something like this:

IN([Thing], UNIQUE(not done task[Before]))

I include the use of UNIQUE() to keep the returned list as small as possible for efficiency