How do I add a filter column as a AND criteria

[#1]

The syntax for Add Filter dictates that the new columns must be in the OR criteria.

Is there some way I can add rules in an iterative way?

dtf<<Add Filter(columns(column <,col>), <Where(clause)>)

Add one or more filter columns in a new OR group.

[#2]

Here's one way:

// AND
df << removeLocalDataFilter;
colList = {"age", "sex"};
CMD = 
Expr(
	df = gb << Local Data Filter(
		Add Filter( columns( colsTBD ) )
		)
	);
SubstituteInto(CMD, Expr(colsTBD), colList);
CMD;

[#3]

I fail to understand the fundamental difference between

1)

df = gb << Local Data Filter(Add Filter(columns({"age", "sex", "name"})));

and

2)

colList = {"age", "sex", "name"};

df = gb << Local Data Filter(Add Filter(columns(colList)));

1) works and 2) does not.

Would you please explain WHY?

Thank you for your help!