Combining three columns in one

[xariet]

I need to create a combined column in Alteryx (blue on my spreadsheet). Any help appreciated. Thanks!

[Qiu · Accepted solution]

@xariet 
We can a transpose then filter out the "NULL" values.

[binuacs]

@xariet another way of doing this.

Note: I updated the text null to Null() in the input