When you enter a Skip formula, you can filter records by Skip as well as identify the source column for each Skip you created in the mapping section.
Skips the given row.
Example 1:= if(equals($"Cost", 0), skip(), $"Cost") = [skips row OR lists cost]
Skipping a row means the row will not be included in the output.
Here is the Skip Feature in action.
Osmos Skip Feature